I experience this as well with flatpak install on fedora Kinoite 37,  kdenlive version 22.08.03.

Logs from startups with and without GPU playback enabled are here:

GPU playback box un-ticked
````
flatpak run --verbose org.kde.kdenlive
F: No installations directory in /etc/flatpak/installations.d. Skipping
F: Opening system flatpak installation at path /var/lib/flatpak
F: Opening user flatpak installation at path /home/Jacob/.local/share/flatpak
F: Opening user flatpak installation at path /home/Jacob/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: Skipping parental controls check for app/org.kde.kdenlive/x86_64/stable since parental controls are disabled globally
F: Opening user flatpak installation at path /home/Jacob/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: /var/lib/flatpak/runtime/org.kde.Platform/x86_64/5.15-21.08/a6e1676859d826a5a2d64cefce1feabb32fde8fe97f73360ba75c262051f510b/files/lib32 does not exist
F: Cleaning up unused container id 2079801115
F: Cleaning up per-app-ID state for org.kde.kdenlive
F: Allocated instance id 1328489954
F: Add defaults in dir /org/kde/kdenlive/
F: Add locks in dir /org/kde/kdenlive/
F: Allowing host-fs access
F: Allowing wayland access
F: Allowing x11 access
F: Allowing pulseaudio access
F: Pulseaudio user configuration file '/home/Jacob/.config/pulse/client.conf': Error opening file /home/Jacob/.config/pulse/client.conf: Ingen slik fil eller filkatalog
F: Running 'bwrap --args 56 xdg-dbus-proxy --args=58'
F: Running 'bwrap --args 56 kdenlive'
QIBusPlatformInputContext: invalid portal bus.
QSocketNotifier: Can only be used with threads started with QThread
=== /// CANNOT ACCESS SPEECH DICTIONARIES FOLDER
profilePath from KdenliveSetting::mltPath:  "/app/share/mlt-7/profiles"
meltPath from KdenliveSetting::rendererPath:  "/app/bin/melt"
Empty metadata for  "avcolour_space"
Empty metadata for  "avcolor_space"
Empty metadata for  "avdeinterlace"
Empty metadata for  "swscale"
Empty metadata for  "swresample"
Empty metadata for  "audiochannels"
Empty metadata for  "audioconvert"
Empty metadata for  "imageconvert"
Empty metadata for  "glsl.manager"
Empty metadata for  "movit.convert"
Empty metadata for  "movit.crop"
Empty metadata for  "movit.resample"
Empty metadata for  "movit.resize"
Empty metadata for  "telecide"
Empty metadata for  "deinterlace"
plugin not available: "avfilter.acompressor"
plugin not available: "avfilter.aecho"
plugin not available: "avfilter.agate"
plugin not available: "avfilter.atadenoise"
plugin not available: "avfilter.bs2b"
plugin not available: "avfilter.bwdif"
plugin not available: "avfilter.deblock"
plugin not available: "avfilter.dedot"
plugin not available: "avfilter.deflate"
plugin not available: "avfilter.derain"
plugin not available: "avfilter.doubleweave"
plugin not available: "avfilter.field"
plugin not available: "avfilter.framestep"
plugin not available: "avfilter.fspp"
plugin not available: "avfilter.graphmonitor"
plugin not available: "avfilter.hqdn3d"
plugin not available: "avfilter.inflate"
plugin not available: "avfilter.lagfun"
plugin not available: "avfilter.loudnorm"
plugin not available: "avfilter.random"
plugin not available: "avfilter.removegrain"
plugin not available: "avfilter.separatefields"
plugin not available: "avfilter.shuffleplanes"
plugin not available: "avfilter.sofalizer"
plugin not available: "avfilter.sr"
plugin not available: "avfilter.tmix"
plugin not available: "avfilter.w3fdif"
plugin not available: "avfilter.weave"
plugin not available: "avfilter.yadif"
plugin not available: "frei0r.baltan"
plugin not available: "frei0r.bgsubtract0r"
plugin not available: "frei0r.bigsh0t_eq_to_stereo"
plugin not available: "frei0r.delay0r"
plugin not available: "frei0r.delaygrab"
plugin not available: "frei0r.facebl0r"
plugin not available: "frei0r.facedetect"
plugin not available: "frei0r.lightgraffiti"
plugin not available: "frei0r.lightgraffiti"
plugin not available: "frei0r.tehRoxx0r"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "movit.unsharp_mask"
plugin not available: "region"
plugin not available: "timewarp"
plugin not available: "region"
QQmlEngine::setContextForObject(): Object already has a QQmlContext
kf.config.core: "KConfigIni: In file /usr/share/kservices5/searchproviders/google_advanced.desktop, line 136: " "Invalid escape sequence \"\\{\"."
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QQmlEngine::setContextForObject(): Object already has a QQmlContext
```

GPU playback box being ticked midway, kdenlive restart and crash:
```
flatpak run --verbose org.kde.kdenlive                                                                                                                                                             ✘ 130
F: No installations directory in /etc/flatpak/installations.d. Skipping
F: Opening system flatpak installation at path /var/lib/flatpak
F: Opening user flatpak installation at path /home/Jacob/.local/share/flatpak
F: Opening user flatpak installation at path /home/Jacob/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: Skipping parental controls check for app/org.kde.kdenlive/x86_64/stable since parental controls are disabled globally
F: Opening user flatpak installation at path /home/Jacob/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: /var/lib/flatpak/runtime/org.kde.Platform/x86_64/5.15-21.08/a6e1676859d826a5a2d64cefce1feabb32fde8fe97f73360ba75c262051f510b/files/lib32 does not exist
F: Cleaning up unused container id 1328489954
F: Cleaning up per-app-ID state for org.kde.kdenlive
F: Allocated instance id 3174169949
F: Add defaults in dir /org/kde/kdenlive/
F: Add locks in dir /org/kde/kdenlive/
F: Allowing host-fs access
F: Allowing wayland access
F: Allowing x11 access
F: Allowing pulseaudio access
F: Pulseaudio user configuration file '/home/Jacob/.config/pulse/client.conf': Error opening file /home/Jacob/.config/pulse/client.conf: Ingen slik fil eller filkatalog
F: Running 'bwrap --args 56 xdg-dbus-proxy --args=58'
F: Running 'bwrap --args 56 kdenlive'
QIBusPlatformInputContext: invalid portal bus.
QSocketNotifier: Can only be used with threads started with QThread
=== /// CANNOT ACCESS SPEECH DICTIONARIES FOLDER
profilePath from KdenliveSetting::mltPath:  "/app/share/mlt-7/profiles"
meltPath from KdenliveSetting::rendererPath:  "/app/bin/melt"
Empty metadata for  "avcolour_space"
Empty metadata for  "avcolor_space"
Empty metadata for  "avdeinterlace"
Empty metadata for  "swscale"
Empty metadata for  "swresample"
Empty metadata for  "audiochannels"
Empty metadata for  "audioconvert"
Empty metadata for  "imageconvert"
Empty metadata for  "glsl.manager"
Empty metadata for  "movit.convert"
Empty metadata for  "movit.crop"
Empty metadata for  "movit.resample"
Empty metadata for  "movit.resize"
Empty metadata for  "telecide"
Empty metadata for  "deinterlace"
plugin not available: "avfilter.acompressor"
plugin not available: "avfilter.aecho"
plugin not available: "avfilter.agate"
plugin not available: "avfilter.atadenoise"
plugin not available: "avfilter.bs2b"
plugin not available: "avfilter.bwdif"
plugin not available: "avfilter.deblock"
plugin not available: "avfilter.dedot"
plugin not available: "avfilter.deflate"
plugin not available: "avfilter.derain"
plugin not available: "avfilter.doubleweave"
plugin not available: "avfilter.field"
plugin not available: "avfilter.framestep"
plugin not available: "avfilter.fspp"
plugin not available: "avfilter.graphmonitor"
plugin not available: "avfilter.hqdn3d"
plugin not available: "avfilter.inflate"
plugin not available: "avfilter.lagfun"
plugin not available: "avfilter.loudnorm"
plugin not available: "avfilter.random"
plugin not available: "avfilter.removegrain"
plugin not available: "avfilter.separatefields"
plugin not available: "avfilter.shuffleplanes"
plugin not available: "avfilter.sofalizer"
plugin not available: "avfilter.sr"
plugin not available: "avfilter.tmix"
plugin not available: "avfilter.w3fdif"
plugin not available: "avfilter.weave"
plugin not available: "avfilter.yadif"
plugin not available: "frei0r.baltan"
plugin not available: "frei0r.bgsubtract0r"
plugin not available: "frei0r.bigsh0t_eq_to_stereo"
plugin not available: "frei0r.delay0r"
plugin not available: "frei0r.delaygrab"
plugin not available: "frei0r.facebl0r"
plugin not available: "frei0r.facedetect"
plugin not available: "frei0r.lightgraffiti"
plugin not available: "frei0r.lightgraffiti"
plugin not available: "frei0r.tehRoxx0r"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "ladspa"
plugin not available: "movit.unsharp_mask"
plugin not available: "region"
plugin not available: "timewarp"
plugin not available: "region"
QQmlEngine::setContextForObject(): Object already has a QQmlContext
kf.config.core: "KConfigIni: In file /usr/share/kservices5/searchproviders/google_advanced.desktop, line 136: " "Invalid escape sequence \"\\{\"."
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QGradient::setColorAt: Color position must be specified in the range 0 to 1
QQmlEngine::setContextForObject(): Object already has a QQmlContext
detected format: Motion-JPEG: MJPG
Size: 1920x1080: 1/30,
Size: 160x120: 1/30,
Size: 176x144: 1/30,
Size: 320x240: 1/30,
Size: 352x288: 1/30,
Size: 640x360: 1/30,
Size: 640x480: 1/30,
Size: 1280x720: 1/30,
Size: 1280x1024: 1/30,
detected format: YUYV 4:2:2: YUYV
Size: 1920x1080: 1/5,
Size: 160x120: 1/30,
Size: 176x144: 1/30,
Size: 320x240: 1/30,
Size: 352x288: 1/30,
Size: 640x360: 1/30,
Size: 640x480: 1/30,
Size: 1280x720: 1/10,
Size: 1280x1024: 1/5,
=== /// CANNOT ACCESS SPEECH DICTIONARIES FOLDER
Invalid button configuration: kf.notifications: Audio notification requested, but sound file from notifyrc file was not found, aborting audio notification
qrc:/qml/timeline.qml:1643: TypeError: Cannot call method 'isSubtitleTrack' of null
qrc:/qml/timeline.qml:977: TypeError: Cannot call method 'isSubtitleTrack' of null
QPaintDevice: Cannot destroy paint device that is being painted

```

GPU playback box ticked previous run. Asked to reset configuration file:
```
flatpak run --verbose org.kde.kdenlive
F: No installations directory in /etc/flatpak/installations.d. Skipping
F: Opening system flatpak installation at path /var/lib/flatpak
F: Opening user flatpak installation at path /home/Jacob/.local/share/flatpak
F: Opening user flatpak installation at path /home/Jacob/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: Skipping parental controls check for app/org.kde.kdenlive/x86_64/stable since parental controls are disabled globally
F: Opening user flatpak installation at path /home/Jacob/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: /var/lib/flatpak/runtime/org.kde.Platform/x86_64/5.15-21.08/a6e1676859d826a5a2d64cefce1feabb32fde8fe97f73360ba75c262051f510b/files/lib32 does not exist
F: Cleaning up unused container id 3174169949
F: Cleaning up per-app-ID state for org.kde.kdenlive
F: Allocated instance id 703392233
F: Add defaults in dir /org/kde/kdenlive/
F: Add locks in dir /org/kde/kdenlive/
F: Allowing host-fs access
F: Allowing wayland access
F: Allowing x11 access
F: Allowing pulseaudio access
F: Pulseaudio user configuration file '/home/Jacob/.config/pulse/client.conf': Error opening file /home/Jacob/.config/pulse/client.conf: Ingen slik fil eller filkatalog
F: Running 'bwrap --args 56 xdg-dbus-proxy --args=58'
F: Running 'bwrap --args 56 kdenlive'
QIBusPlatformInputContext: invalid portal bus.
QSocketNotifier: Can only be used with threads started with QThread
 = = = =
GOT Deleted file:  "/home/Jacob/.var/app/org.kde.kdenlive/config/kdenlive-flatpakrc"
 = = = =
GOT Deleted file:  "/app/share/kxmlgui5/kdenlive/kdenliveui.rc"
QPaintDevice: Cannot destroy paint device that is being painted
```

My environment:
```
Operating System: Fedora Linux 37 Kinoite
KDE Plasma Version: 5.26.4
KDE Frameworks Version: 5.100.0
Qt Version: 5.15.7
Kernel Version: 6.0.11-300.fc37.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 12 × Intel® Core™ i7-8750H CPU @ 2.20GHz
Memory: 31.1 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 630
Manufacturer: Notebook
Product Name: P95xER
System Version: Not Applicable
```


output of inxi -Fazy
```
System:
  Kernel: 6.0.11-300.fc37.x86_64 arch: x86_64 bits: 64 compiler: gcc
    v: 2.38-25.fc37
    parameters: BOOT_IMAGE=(hd2,gpt2)/ostree/fedora-6cfd2d05e1997192080ce9362d9c0ede59b51ba4de7928bb0bf23c73b89f91f5/vmlinuz-6.0.11-300.fc37.x86_64
    rd.luks.uuid=luks-ac2be2a2-3a0d-463c-a10e-db33888ea41d rhgb quiet
    root=UUID=ab093a6e-4634-4015-bcc4-9cd2d90a1c94 rootflags=subvol=root
    dev.i915.perf_stream_paranoid=0
    ostree=/ostree/boot.1/fedora/6cfd2d05e1997192080ce9362d9c0ede59b51ba4de7928bb0bf23c73b89f91f5/0
    rd.driver.blacklist=nouveau modprobe.blacklist=nouveau
    nvidia-drm.modeset=1 rw
  Desktop: KDE Plasma v: 5.26.4 tk: Qt v: 5.15.7 wm: kwin_wayland vt: 1
    dm: SDDM Distro: Fedora release 37 (Thirty Seven)
Machine:
  Type: Laptop System: Notebook product: P95xER v: N/A
    serial: <superuser required> Chassis: No Enclosure type: 10
    serial: <superuser required>
  Mobo: Notebook model: P95xER serial: <superuser required>
    UEFI: American Megatrends v: 1.07.15 date: 11/16/2018
Battery:
  ID-1: BAT0 charge: 36.3 Wh (90.5%) condition: 40.1/53.2 Wh (75.3%)
    volts: 16.3 min: 15.2 model: Notebook BAT type: Li-ion serial: <filter>
    status: not charging
  Device-1: hidpp_battery_0 model: Logitech Wireless Touch Keyboard K400
    serial: <filter> charge: 100% (should be ignored) rechargeable: yes
    status: discharging
CPU:
  Info: model: Intel Core i7-8750H bits: 64 type: MT MCP arch: Coffee Lake
    gen: core 8 level: v3 note: check built: 2018 process: Intel 14nm family: 6
    model-id: 0x9E (158) stepping: 0xA (10) microcode: 0xF0
  Topology: cpus: 1x cores: 6 tpc: 2 threads: 12 smt: enabled cache:
    L1: 384 KiB desc: d-6x32 KiB; i-6x32 KiB L2: 1.5 MiB desc: 6x256 KiB
    L3: 9 MiB desc: 1x9 MiB
  Speed (MHz): avg: 3553 high: 4037 min/max: 800/4100 scaling:
    driver: intel_pstate governor: powersave cores: 1: 4001 2: 4000 3: 2200
    4: 4001 5: 4002 6: 4000 7: 4001 8: 2200 9: 2200 10: 4001 11: 4000 12: 4037
    bogomips: 52799
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
  Vulnerabilities:
  Type: itlb_multihit status: KVM: VMX disabled
  Type: l1tf mitigation: PTE Inversion; VMX: conditional cache flushes, SMT
    vulnerable
  Type: mds mitigation: Clear CPU buffers; SMT vulnerable
  Type: meltdown mitigation: PTI
  Type: mmio_stale_data mitigation: Clear CPU buffers; SMT vulnerable
  Type: retbleed mitigation: IBRS
  Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via
    prctl
  Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer
    sanitization
  Type: spectre_v2 mitigation: IBRS, IBPB: conditional, RSB filling,
    PBRSB-eIBRS: Not affected
  Type: srbds mitigation: Microcode
  Type: tsx_async_abort status: Not affected
Graphics:
  Device-1: Intel CoffeeLake-H GT2 [UHD Graphics 630] vendor: CLEVO/KAPOK
    driver: i915 v: kernel arch: Gen-9.5 process: Intel 14nm built: 2016-20
    ports: active: eDP-1 empty: none bus-ID: 00:02.0 chip-ID: 8086:3e9b
    class-ID: 0300
  Device-2: NVIDIA GP104M [GeForce GTX 1070 Mobile] vendor: CLEVO/KAPOK
    driver: nvidia v: 520.56.06 alternate: nouveau,nvidia_drm non-free: 520.xx+
    status: current (as of 2022-10) arch: Pascal code: GP10x process: TSMC 16nm
    built: 2016-21 pcie: gen: 1 speed: 2.5 GT/s lanes: 16 link-max: gen: 3
    speed: 8 GT/s ports: active: none empty: DP-1,DP-2,HDMI-A-1 bus-ID: 01:00.0
    chip-ID: 10de:1ba1 class-ID: 0300
  Device-3: Chicony USB 2.0 Camera type: USB driver: uvcvideo bus-ID: 1-8:4
    chip-ID: 04f2:b5a7 class-ID: 0e02
  Display: wayland server: X.org v: 1.20.14 with: Xwayland v: 22.1.5
    compositor: kwin_wayland driver: X: loaded: modesetting,nvidia
    unloaded: fbdev,nouveau,vesa alternate: nv dri: iris gpu: i915,nvidia
    display-ID: 0
  Monitor-1: eDP-1 res: 1920x1080 size: N/A modes: N/A
  API: OpenGL v: 4.6 Mesa 22.2.3 renderer: Mesa Intel UHD Graphics 630 (CFL
    GT2) direct render: Yes
Audio:
  Device-1: Intel Cannon Lake PCH cAVS vendor: CLEVO/KAPOK
    driver: snd_hda_intel v: kernel alternate: snd_soc_skl,snd_sof_pci_intel_cnl
    bus-ID: 00:1f.3 chip-ID: 8086:a348 class-ID: 0403
  Device-2: NVIDIA GP104 High Definition Audio driver: snd_hda_intel
    v: kernel pcie: gen: 1 speed: 2.5 GT/s lanes: 16 link-max: gen: 3
    speed: 8 GT/s bus-ID: 01:00.1 chip-ID: 10de:10f0 class-ID: 0403
  Sound API: ALSA v: k6.0.11-300.fc37.x86_64 running: yes
  Sound Server-1: PulseAudio v: 16.1 running: no
  Sound Server-2: PipeWire v: 0.3.61 running: yes
Network:
  Device-1: Intel Wireless-AC 9260 vendor: Rivet Networks driver: iwlwifi
    v: kernel pcie: gen: 2 speed: 5 GT/s lanes: 1 bus-ID: 03:00.0
    chip-ID: 8086:2526 class-ID: 0280
  IF: wlp3s0 state: up mac: <filter>
  Device-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet
    vendor: CLEVO/KAPOK driver: r8169 v: kernel pcie: gen: 1 speed: 2.5 GT/s
    lanes: 1 port: 3000 bus-ID: 04:00.0 chip-ID: 10ec:8168 class-ID: 0200
  IF: enp4s0 state: down mac: <filter>
Bluetooth:
  Device-1: Intel Wireless-AC 9260 Bluetooth Adapter type: USB driver: btusb
    v: 0.8 bus-ID: 1-14:6 chip-ID: 8087:0025 class-ID: e001
  Report: rfkill ID: hci0 rfk-id: 0 state: down bt-service: enabled,running
    rfk-block: hardware: no software: yes address: see --recommends
Drives:
  Local Storage: total: 2.96 TiB used: 747.72 GiB (24.7%)
  SMART Message: Unable to run smartctl. Root privileges required.
  ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Samsung model: SSD 960 EVO 250GB
    size: 232.89 GiB block-size: physical: 512 B logical: 512 B speed: 31.6 Gb/s
    lanes: 4 type: SSD serial: <filter> rev: 3B7QCXE7 temp: 38.9 C scheme: GPT
  ID-2: /dev/sda maj-min: 8:0 vendor: Seagate model: ST2000LX001-1RG174
    size: 1.82 TiB block-size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s
    type: HDD rpm: 5400 serial: <filter> rev: SDM1
  ID-3: /dev/sdb maj-min: 8:16 type: USB vendor: Toshiba model: MQ01UBD100
    size: 931.51 GiB block-size: physical: 512 B logical: 512 B type: HDD
    rpm: 5400 serial: <filter> scheme: GPT
Partition:
  ID-1: /boot raw-size: 1024 MiB size: 973.4 MiB (95.06%)
    used: 172.4 MiB (17.7%) fs: ext4 dev: /dev/nvme0n1p2 maj-min: 259:2
  ID-2: /boot/efi raw-size: 600 MiB size: 598.8 MiB (99.80%)
    used: 9.8 MiB (1.6%) fs: vfat dev: /dev/nvme0n1p1 maj-min: 259:1
Swap:
  Kernel: swappiness: 60 (default) cache-pressure: 100 (default)
  ID-1: swap-1 type: zram size: 8 GiB used: 0 KiB (0.0%) priority: 100
    dev: /dev/zram0
Sensors:
  System Temperatures: cpu: 49.0 C pch: 57.0 C mobo: N/A
  Fan Speeds (RPM): N/A
Info:
  Processes: 408 Uptime: 1h 12m wakeups: 5 Memory: 31.07 GiB
  used: 8.26 GiB (26.6%) Init: systemd v: 251 target: graphical (5)
  default: graphical tool: systemctl Compilers: gcc: 12.2.1 Packages: pm: rpm
  pkgs: N/A note: see --rpm pm: flatpak pkgs: 83 Shell: Zsh v: 5.9
  running-in: alacritty inxi: 3.3.23
```

GPU playback is not implemented so far. GPU encoding is on the roadmap. So, switch it off for the time being.