SUMMARY *** Interrupting the monitor power save at the right moment puts the system into input-blocked state. *** STEPS TO REPRODUCE 1. wiggle mouse during the short screen dimming animation, before the power save OBSERVED RESULT Keyboard is totally locked out, including ctrl-alt-Fkeys to switch TTY. Mouse cursor can move but buttons are blocked. System is still responsive, and Plasma GUI shows hover animations (such as thumbnail pop-ups on the taskbar) and other signs of life. With no way to interact with system, a reset is the only apparent escape. The system returns to normal if a second monitor power save cycle completes. In normal use this won't be obvious since it involves a long wait. SOFTWARE/OS VERSIONS Linux/KDE Plasma: 5.19.13-1-MANJARO x86_64 KDE Plasma Version: Plasma 5.25.5 ADDITIONAL INFORMATION Reproduce by setting the monitor power save to 1 minute and use phone stopwatch to time the mouse wiggle :)
Thank you for the bug report! Please note that Plasma 5.25.5 is not supported for much longer by KDE; supported versions are 5.24, and 5.26 or newer. If at all possible please upgrade to a supported version and verify that the bug is still happening there.
Seems to be fixed on Plasma 5.26.2