Created attachment 170962 [details]
KDE Plasma 6.1 desktop with the application launcher, hidden icons panel, & taskbar displayed as pure black boxes. Hidden icons panel & application launcher are closed but the boxes are still there.

Not sure I'm putting the this in the right product category, I hope kwin is correct.

SUMMARY
Taskbar & things that pop out from it show as black boxes after upgrade from Plasma 6.0 to 6.1. I upgraded my KDE Neon install from Plasma 6.0 to Plasma 6.1 the day after it released through the Discover app. Since then, my taskbar & most of the menus that can pop out of it, including the application launcher, hidden icons tray, weather, clipboard contents, and any tooltips in those menus draw to the screen as pure black nothing. These black boxes appear on top of everything no matter what, except for certain apps which can "erase" these boxes almost like you would erase in an image editor by dragging their windows over them. Attached screenshot shows the issue the worst it can get.

STEPS TO REPRODUCE
1. Upgrade KDE Neon from Plasma 6.0 to Plasma 6.1
2. Restart computer, boot completely normally
3. Log in

OBSERVED RESULT
Taskbar is now black, anything that comes out of it is black. It's all still interactable if you know where the buttons are. Open the desktop switcher by moving the cursor to the top left corner & select your current desktop again to temporarily make the taskbar & its menus normal again.

EXPECTED RESULT
Taskbar should appear with all its buttons & pinned programs normally, application manager & other menus that come out of or are attached to the taskbar should also be the same.

SOFTWARE/OS VERSIONS
OS: KDE Neon 6.0
KDE Plasma Version: 6.1.0
KDE Frameworks Version: 6.3.0
Qt Version: 6.7.0
Kernel Version: 6.5.0-41-generic (64bit)
Graphics Platform: Wayland or X11

ADDITIONAL INFORMATION
I usually use Wayland, but I have switched to X11 from the login screen & it happens in that too.

I can make all of these black menus turn back to normal temporarily by opening them, then moving my cursor to the top left corner to open the desktop switcher, then picking my current desktop again by clicking an empty space in it. I have to do this each time I open a menu from the taskbar in order to see it, or sometimes to restore the taskbar's visibility too. Occasionally opening one of these menus or allowing a tooltip to appear will cause the black boxes to "infect" the rest of the taskbar & very quickly turn it all black. On further examination the boxes appear to be transparencies (at least in the screenshot), not opaque black, but they appear as black on my display & cover other windows, preventing them from being seen.

Incase hardware is relevant, my CPU is an AMD A6-3622 & my graphics processor is an integrated AMD Radeon HD 6530D. Info Center reports my graphics processor as "AMD SUMO". This is an old Acer Aspire X1470.