SUMMARY
Brightness control for my external Philiphs monitor sometimes appears in the applet, but sometimes disappears. When the slider isn't there, the brightness set on the monitor is overwritten to 100%.
It's plugged in to HDMI to the dGPU.

Graphics:
  Device-1: Intel Raptor Lake-P [UHD Graphics] vendor: AIstone Global
    driver: i915 v: kernel alternate: xe arch: Gen-13 process: Intel 7 (10nm)
    built: 2022+ ports: active: eDP-1 empty: none bus-ID: 00:02.0
    chip-ID: 8086:a7a8 class-ID: 0300
  Device-2: NVIDIA AD107M [GeForce RTX 4060 Max-Q / Mobile]
    vendor: AIstone Global driver: nvidia v: 550.127.05
    alternate: nouveau,nvidia_drm non-free: 550.xx+
    status: current (as of 2024-09) arch: Lovelace code: AD1xx
    process: TSMC n4 (5nm) built: 2022+ pcie: gen: 1 speed: 2.5 GT/s lanes: 8
    link-max: gen: 4 speed: 16 GT/s ports: active: none off: HDMI-A-1
    empty: DP-1,eDP-2 bus-ID: 01:00.0 chip-ID: 10de:28a0 class-ID: 0300
  Device-3: SunplusIT HD Webcam driver: uvcvideo type: USB rev: 2.0
    speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 1-5:3 chip-ID: 2b7e:b651
    class-ID: 0e02 serial: <filter>
  Display: wayland server: X.org v: 1.21.1.14 with: Xwayland v: 24.1.4
    compositor: kwin_wayland driver: X: loaded: modesetting,nvidia
    unloaded: vesa alternate: fbdev,intel,nouveau,nv dri: iris
    gpu: i915,nvidia d-rect: 3572x2009 display-ID: 0
  Monitor-1: HDMI-A-1 pos: primary,top-left res: 1920x1080 size: N/A
    modes: N/A
  Monitor-2: eDP-1 pos: bottom-r res: 1652x929 size: N/A modes: N/A
  API: EGL v: 1.5 hw: drv: intel iris drv: nvidia platforms: device: 0
    drv: nvidia device: 1 drv: iris gbm: drv: iris surfaceless: drv: nvidia
    wayland: drv: iris x11: drv: iris
  API: OpenGL v: 4.6.0 compat-v: 4.6 vendor: intel mesa v: 24.3.0 glx-v: 1.4
    direct-render: yes renderer: Mesa Intel Graphics (RPL-P)
    device-ID: 8086:a7a8 memory: 15.17 GiB unified: yes display-ID: :1.0
  API: Vulkan v: 1.3.296 layers: 6 device: 0 type: integrated-gpu
    name: Intel Graphics (RPL-P) driver: N/A device-ID: 8086:a7a8
    surfaces: xcb,xlib,wayland device: 1 type: discrete-gpu name: NVIDIA
    GeForce RTX 4060 Laptop GPU driver: N/A device-ID: 10de:28a0
    surfaces: xcb,xlib,wayland

Operating System: openSUSE Tumbleweed 20241203
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.8.0
Qt Version: 6.8.0
Kernel Version: 6.11.8-1-default (64-bit)
Graphics Platform: Wayland
Processors: 16 × 13th Gen Intel® Core™ i7-13620H
Memory: 31,1 GiB of RAM
Graphics Processor: Mesa Intel® Graphics
Manufacturer: SLIMBOOK
Product Name: HERO-RPL-RTX