lock up

Good afternoon, I am using Ubuntu 24.04 and when I lock the screen with Ctrl + L, it simply says that my password is incorrect even though it isn’t. I have already updated KDE to the latest version, and it still doesn’t work at all.

Okay, I hope these are not too difficult. First off, for some reason when I'm away from this thing for an extended period, screensaver will not engage. I've played with the timing and it still sits on/in same mode when I left. The second matter is if I try to put this in sleep mode (I know, I...