This is going to be a local configuration issue, as something so basic can't be globally broken for everyone or else there would be ten million bug reports. Needless to say, it's all working for me.

We need more information about the conditions under which this issue happens for you. Please try some basic troubleshooting, such as switching to a different window switcher theme, using a new clean user account on the same computer, trying the Wayland session, and so on.

> switching to a different window switcher theme

Only these two switchers don't work: Compact, Large Icons. I prefer Compact.

Preview of `Compact` works when I click the thumbnail button next to the task switcher drop-down in the KCM.

`Compact` works on a different laptop (Debian).

I am able to cause the task switcher to disappear when alternating between "Walk Through Windows" and "Walk Through Windows of Current Application" without releasing tab. I guess my comment belongs in this report.

STEPS TO REPRODUCE:
I think my binds are are the default (Alt+Tab and Alt+` respectively).
1. Open at least two windows of the same application (easier to trigger but not required as long as any two or more windows are open).
2. Press Alt+Tab, and keep holding alt. The task switcher should now be highlighting the second window in the list.
3. Without releasing alt, now press `

OBSERVED RESULT
The currently-selected window is shown (if "Show selected window" is enabled), but the task switcher visualization is no longer visible.

EXPECTED RESULT
For the task switcher to remain visible 

SOFTWARE/OS VERSIONS
Operating System: EndeavourOS (Arch Linux)
KDE Plasma Version: 6.4.4
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.1
Kernel Version: 6.16.2-273-linux-tkg (64-bit) (Persists across kernels)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 5800X3D 8-Core Processor
Memory: 64 GiB of RAM (62.7 GiB usable)
Graphics Processor: AMD Radeon RX 7800 XT
Manufacturer: Micro-Star International Co., Ltd.
Product Name: MS-7C56
System Version: 6.0

ADDITIONAL INFORMATION
Changing between task switcher visualizations does not seem to make a difference. I usually use Thumbnail Grid but can trigger it on Compact, Cover Switch, Flip Switch, Large Icons, and Sidebar too. Cover Switch And Flip Switch might be the most jarring due to the different way they visualize compared to the others, only for the visualization to disappear.

Changing any of the other settings in the Task Switcher settings did not seem to make a difference.

Please include output of `journalctl --user -u plasma-kwin_wayland -r` after attempting to use the tabbox

(In reply to David Edmundson from comment #4)
> Please include output of `journalctl --user -u plasma-kwin_wayland -r` after
> attempting to use the tabbox

There does not seem to be any output from that command generated at the time I make the task switcher disappear. The most recent lines (Over 15 minutes before reproducing the issue again) are:
Aug 28 23:37:40 Lalatina kwin_wayland[1367038]: kf.windowsystem: static bool KX11Extras::mapViewport() may only be used on X11
Aug 28 23:30:17 Lalatina kwin_wayland[1367038]: kf.windowsystem: static bool KX11Extras::mapViewport() may only be used on X11
Aug 28 23:30:07 Lalatina kwin_wayland[1367038]: kf.windowsystem: static bool KX11Extras::mapViewport() may only be used on X11
Aug 28 23:29:59 Lalatina kwin_wayland[1367038]: kf.windowsystem: static bool KX11Extras::mapViewport() may only be used on X11
Aug 28 23:29:11 Lalatina kwin_wayland[1367038]: kwin_xwl: Could not create a source from 0x6081646bc7b0 0

These yellow warning messages were likely generated from opening OBS and virt-manager in XWayland for the keyboard visualization in the next paragraph.

Additionally, I have reproduced the issue in the live CD of KDE Neon User Edition (neon-user-20250803-0744) inside a virtual machine. Here is a video recording with a keyboard visualization: https://www.youtube.com/watch?v=IuU44Nefq3Q
Note: The virtual keyboard didn't highlight grave accent/tilde for some reason so for visualization purposes I rebound "Walk Through Windows of Current Application" to Alt+1/Alt+!.

Additional information that I failed to clarify earlier: If the currently-highlighted window is the first in the task switcher's list (e.g. you pressed alt+tab followed by alt+shift+tab) and then pressed Alt+`, the visualization will work normally.

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

Thank you for helping us make KDE software even better for everyone!

🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.

Reproducible on Wayland + Fedora 42.



```
$ journalctl --user -u plasma-kwin_wayland -r
окт 25 22:20:31 glue.infernonlvps kwin_wayland[22362]: kf.package: Could not find required file "mainscript" for package "/usr/local/share/kwin/tabbox/compact/" should be QList("ui/main.qml")
окт 25 22:20:05 glue.infernonlvps kwin_wayland[22362]: kf.package: Could not find required file "mainscript" for package "/usr/local/share/kwin/tabbox/compact/" should be QList("ui/main.qml")
окт 25 22:19:22 glue.infernonlvps kwin_wayland[22362]: kf.package: Could not find required file "mainscript" for package "/usr/local/share/kwin/tabbox/big_icons/" should be QList("ui/main.qml")
окт 25 22:19:06 glue.infernonlvps kwin_wayland[22362]: kf.package: Could not find required file "mainscript" for package "/usr/local/share/kwin/tabbox/compact/" should be QList("ui/main.qml")
окт 25 22:19:03 glue.infernonlvps kwin_wayland[22362]: kf.package: Could not find required file "mainscript" for package "/usr/local/share/kwin/tabbox/compact/" should be QList("ui/main.qml")
окт 25 22:19:00 glue.infernonlvps kwin_wayland[22362]: kf.package: Could not find required file "mainscript" for package "/usr/local/share/kwin/tabbox/compact/" should be QList("ui/main.qml")
окт 25 22:18:57 glue.infernonlvps kwin_wayland[22362]: kf.package: Could not find required file "mainscript" for package "/usr/local/share/kwin/tabbox/compact/" should be QList("ui/main.qml")
окт 25 22:18:54 glue.infernonlvps kwin_wayland[22362]: kf.package: Could not find required file "mainscript" for package "/usr/local/share/kwin/tabbox/compact/" should be QList("ui/main.qml")
окт 25 22:15:28 glue.infernonlvps kwin_wayland[22362]: kwin_libinput: Libinput: event8  - Logitech USB Optical Mouse: client bug: event processing lagging behind by 198ms, your system is too slow
окт 25 22:14:06 glue.infernonlvps kwin_wayland[22362]: kwin_libinput: Libinput: event8  - Logitech USB Optical Mouse: client bug: event processing lagging behind by 66ms, your system is too slow
окт 25 22:13:57 glue.infernonlvps maliit-keyboard[22450]: QSGContext::initialize: stencil buffer support missing, expect rendering errors
окт 25 22:13:57 glue.infernonlvps maliit-keyboard[22450]: QSGContext::initialize: depth buffer support missing, expect rendering errors
окт 25 22:13:56 glue.infernonlvps kwin_wayland[22362]: kf.config.core: "\"fsrestore4\" - conversion of \"0,0,0,0\" to QRect failed"
окт 25 22:13:56 glue.infernonlvps kwin_wayland[22362]: kf.config.core: "\"fsrestore3\" - conversion of \"0,0,0,0\" to QRect failed"
окт 25 22:13:56 glue.infernonlvps kwin_wayland[22362]: kf.config.core: "\"fsrestore2\" - conversion of \"0,0,0,0\" to QRect failed"
окт 25 22:13:56 glue.infernonlvps kwin_wayland[22362]: kf.config.core: "\"fsrestore1\" - conversion of \"0,0,0,0\" to QRect failed"
окт 25 22:13:55 glue.infernonlvps maliit-keyboard[22450]: QSoundEffect(pulseaudio): Error decoding source file:///usr/share/maliit/keyboard2/sounds/key_tick2_quiet.wav
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22492]: Errors from xkbcomp are not fatal to the X server
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22492]: > Warning:          Could not resolve keysym XF86DoNotDisturb
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22492]: > Warning:          Could not resolve keysym XF86Accessibility
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22492]: > Warning:          Could not resolve keysym XF86RefreshRateToggle
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22492]: >                   X11 cannot support keycodes above 255.
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22492]: > Warning:          Unsupported maximum keycode 708, clipping.
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22492]: The XKEYBOARD keymap compiler (xkbcomp) reports:
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22483]: Errors from xkbcomp are not fatal to the X server
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22483]: > Warning:          Could not resolve keysym XF86DoNotDisturb
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22483]: > Warning:          Could not resolve keysym XF86Accessibility
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22483]: > Warning:          Could not resolve keysym XF86RefreshRateToggle
окт 25 22:13:52 glue.infernonlvps kwin_wayland_wrapper[22483]: The XKEYBOARD keymap compiler (xkbcomp) reports:
окт 25 22:13:50 glue.infernonlvps kwin_wayland[22362]: No backend specified, automatically choosing drm
окт 25 22:13:50 glue.infernonlvps systemd[22239]: Started plasma-kwin_wayland.service - KDE Window Manager.
окт 25 22:13:50 glue.infernonlvps systemd[22239]: Starting plasma-kwin_wayland.service - KDE Window Manager...
-- Boot c4051c0599834f429f901deb8157e08d --
...
```

kinfo:

Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.19.0
Qt Version: 6.9.2
Kernel Version: 6.17.4-200.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-6700HQ CPU @ 2.60GHz
Memory: 16 ГиБ of RAM (15.4 ГиБ usable)
Graphics Processor 1: Intel® HD Graphics 530
Graphics Processor 2: NVIDIA GeForce GTX 960M

Target path from log has empty directories only:

```
$ find /usr/local/share/kwin/tabbox/compact/
/usr/local/share/kwin/tabbox/compact/
/usr/local/share/kwin/tabbox/compact/contents
/usr/local/share/kwin/tabbox/compact/contents/ui
```

Tabbox is installed in a different path:

```
$ locate kwin/tabbox/compact 
/usr/local/share/kwin/tabbox/compact
/usr/local/share/kwin/tabbox/compact/contents
/usr/local/share/kwin/tabbox/compact/contents/ui
/usr/share/kwin/tabbox/compact
/usr/share/kwin/tabbox/compact/contents
/usr/share/kwin/tabbox/compact/metadata.json
/usr/share/kwin/tabbox/compact/contents/ui
/usr/share/kwin/tabbox/compact/contents/ui/main.qml
```

Looks like KWin Window Switcher KCM shows switcher item from /usr/share/kwin/tabbox/compact/metadata.json, but then KWin tries to find code in a different path /usr/local/share/kwin/tabbox/compact/contents/ui. IMO KWin should treat two installations at different paths as two separate plugins.

Resolved the issue locally with:

```
cd /usr/local/share/kwin &&  sudo rmdir */*/*/* */*/* */* *
```

Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.19.0
Qt Version: 6.9.2
Kernel Version: 6.17.4-200.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-6700HQ CPU @ 2.60GHz
Memory: 16 ГиБ of RAM (15.4 ГиБ usable)
Graphics Processor 1: Intel® HD Graphics 530
Graphics Processor 2: NVIDIA GeForce GTX 960M

It would appear what's happening is that the metadata.json file is installed in the correct place in the /usr version, but the *files* of the /usr/local version are getting used. This is because what's in /usr/local will always override what's in /usr.

There's nothing KWin can do here; you'll just need to remove or update your local fork of the effect in /usr/local.