Leap 42.3 Application Launcher only works when the desktop is empty (all apps minimized)

I just installed leap 42.3/KDE/plasma (clean install from DVD), and the application launcher will only come up when the desktop is empty. If I have applications already up on the desktop, pressing Alt-F1 will cause the launch menu to flash briefly but it doesn’t stay up. Clicking the icon (in the lower left ) with the mouse doesn’t do anything, but a small “Application Launcher” tooltip message appears when I hover over it.

Switching to the alternate launchers does the same thing. Nothing related to this problem shows up in the system log.

Minimizing the active applications makes it work, but I don’t want to do that every time I need to launch a new app. Please tell me this is not normal behavior now…

No, it isn’t.

What settings do you have in “Window Management”->“Window Behavior”?

Setting the stealing prevention to “high” may exactly cause the behavior you describe (which is a long-standing “bug”).

Good call, and many many thanks! That was exactly what the problem was.