Followup-For: Bug #882512
Since I'm keeping the shell open where I run
KWIN_EXPLICIT_SYNC=0 kwin_x11 --replace &
I noticed this message usually appearing before problems start:
QXcbWindow: Unhandled client message: "_NET_CURRENT_DESKTOP"
Google has a few hits for this, but nothing really helpful.
This time also <Alt>+<Tab> stopped working, mouse is still fine.
Andreas