Bug 452418

Created attachment 148059 [details]
The rendering glitch

Dear KDE developers,

I've recently (~3 months) been getting glitchy rendering in window previews as shown in the attached screenshot. I had hoped that this might get fixed with KDE 5.24.4 (I thought this might be https://bugs.kde.org/show_bug.cgi?id=421135) but unfortunately it still happens.


STEPS TO REPRODUCE
1. Open two windows of the same application (so they get grouped)
2. Hover over their task manager entry to bring up the window list (the one with thumbnails)
3. Move the mouse back and forth between the two windows' thumbnails to alternate between their previews (sometimes the glitch happens very quickly, sometimes it takes a minute or two)

OBSERVED RESULT
The window previews occasionally glitch out and get rendered incorrectly.

EXPECTED RESULT
The window previews should get rendered correctly.

SOFTWARE/OS VERSIONS
Linux: Kernel 5.16.12 (x86-64)
KDE Plasma Version: 5.24.4
KDE Frameworks Version: 5.90.0
Qt Version: 5.15.2
Graphics: X11, Mesa 22.0, amdgpu/radeonsi (Radeon Pro W6800)
Monitors have 120Hz refresh rate set (if relevant)