Normally, meta+right is my shortcut to tilt an app window to right half of display
The symptom is this:
start plasma normally
use it for a while, and meta+right is changed to somehow acting like starting a new session which can be accessed by ctrl+alt+f2. I have to ctrl+alt+f1 to go back to my original session.
$ loginctl
SESSION UID USER SEAT LEADER CLASS TTY IDLE SINCE
2 1000 k seat0 1074 user tty1 no -
3 1000 k - 1080 manager - no -
4 961 sddm - 37025 manager-early - no -
5 1000 k seat0 38074 user tty4 no -
c2 961 sddm seat0 37020 greeter tty2 no -