SUMMARY
I recently switched to Wayland after replacing my AMD Radeon R7 240 with an AMD Radeon RX 550. That was about 20 days ago, and the system worked fine at first, but about five days ago I noticed a behavior that became clear today: when the KDE system is configured to turn off the monitor after a certain amount of time, and after that time the system tries to turn off the monitor and gradually reduce its brightness, the system freezes completely. The only solution is to press the reset button on the computer. After rebooting, the system works normally only until the next attempt to automatically turn off the monitor when the computer is idle. In this situation, I had to disable the monitor auto-off feature, because the system only works properly in this case.

STEPS TO REPRODUCE
1. The system is configured to automatically turn off the monitor after a few minutes.
2. When the timer expires, the monitor goes half dark and the system freezes completely.

OBSERVED RESULT
The system freezes completely.

EXPECTED RESULT
The monitor should smoothly turn off and turn on again at the user's request from the mouse or keyboard...

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: openSUSE Tumbleweed
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.20.0
Qt Version: 6.10.1

ADDITIONAL INFORMATION
Operating System: openSUSE Tumbleweed 20251211
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.20.0
Qt Version: 6.10.1
Kernel Version: 6.18.0-2-default (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i3-9100F CPU @ 3.60GHz
Memory: 8 GiB of RAM (7.7 ГиБ usable)
Graphics Processor: AMD Radeon RX 550 Series