I've been experiencing problems when the session got locked in debian bullseye with kde.
No need to give to many details but every time I needed to kill kscreenlocker_greet process from a tty and then I guess sddm would restart it again and it would work properly so I could unlock the session from vt7
So being a smartass as I am (

What could go wrong? well... something went wrong. Now kscreenlocker_greet won't start and I need to unlock the session with loginctl unlock-session manually.
I haven't been able to find the problem, not using strace nor gdb (apparently there are no debugging symbols in tha process.
Anybody has any experience debuggind something like this?
Thanks!