Using up-to-date F-35 KDE, some key stroke assignments disappeared on me this afternoon. I was able to restore switch-activities to alt-f1, alt-f2 and alt-f3, but I've been unable to switch virtual terminals (VTs) using my usual cntl-f1...cntl-f4, like I'm used to. I've been looking, but I haven't found the way to assign keyboard shortcuts to switch VTs under System Settings -> Window Management or -> Shortcuts.

I really, REALLY expected to find it under System Settings -> Window Behavior -> Virtual Desktops, but it's not there.

I am able to switch using the task bar, but I prefer key strokes.

Any help is appreciated.

Have a look at System Settings -> Workspace -> Shortcuts -> Kwin

Thank you, Mamarok. As it is, I "accidentally" found the solution - I had locked cntl f1...f4 functions (and that too was accidental). Unlocking did the trick.