Scrolling the mousewheel in a desktop (4 virtual desktops configured) has no effect. The mouse action in the desktop is OK for switching desktops.
This problem has cropped up in Plasma 5 , see KDE bug 419867 and there was a solution in its Comment 65.
I implemented this solution now in Plasma 6. it causes no problems, but it does not resolve the issue either. I logged a new bug 505779 for it.
Just to warn other people if they hit the same snag.
You wrote two statements:
“Scrolling the mousewheel in a desktop (4 virtual desktops configured) has no effect.”
“The mouse action in the desktop is OK for switching desktops.”
Can you clarify what “mouse action in desktop” means? Or that exact setting?
Sorry, it should read: the mouse action in the desktop panel (area showing the four icons for desktops) is OK for switching desktops.
Got answer from KDE: known problem with X11.
I switched to Plasma Wayland, but same problem.