hello,
i dont know what i did but in kate the undo shortcut "ctrl z" isnt working anymore.
however its still in the shortcut list.
Same for "ctrl shift z" aka redo.
if i change the shortcut to e.g "meta ctrl shift z" it works as good as the other shortcuts (like "ctrl s")

I tried resetting the shortcuts as well as restarting kate - nothing has helped so far.
Are there any suggestions?

Just to verify this is not a system wide fault, can you try to reproduce under a new user?