Occasionally I get this on wake from suspend, doesn’t matter if amd or nvidia system.
I just think of it as an annoying kde bug. It’s harmless though.
You either reboot or just switch to another tty and unlock the session.
But the others are right, you increase chances of this happening if you updated the kde stack and didn’t reboot/relog.
Quick, someone make a yt video that explains even less with more confusion and a word from our sponsors!