Bug 486936

Created attachment 169407 [details]
Logs at the moment of display's sleep and unlocking

SUMMARY
When the display turns off, and some time passes (under 15m), usually some application windows are being squished into small sizes, also some in-app panels might change its sizes too. This happens only Wayland session. X11 doesn't have such issue.

STEPS TO REPRODUCE
1. Open some windows
2. Place and resize them as you wish
3. Wait / manually lock screen and wait for it to turn off

OBSERVED RESULT
After unlocking the screen, windows are squished and displaced.

EXPECTED RESULT
After unlocking windows retain their sizes and positions.

SOFTWARE/OS VERSIONS

Linux: Arch Linux
KDE Plasma Version: 6.0.4
KDE Frameworks Version: 6.1.0
Qt Version: 6.7.0

ADDITIONAL INFORMATION
As this issue didn't get reported and (probably) related issues do have low activity, I assume it might be related to the bug, that affects only some hardware and previously caused https://bugs.kde.org/show_bug.cgi?id=452553. 
https://invent.kde.org/plasma/kwin/-/merge_requests/2940

Previously I reported this to https://bugs.kde.org/show_bug.cgi?id=482875, but only now I realized that this is not exactly the same issue, so I decided to report it separately. (However, they might be related.)