Navigate > Class... not working any longer Follow

Hi,

I'm not aware of having run an update in the past week, but now somehow all the top items from Navigation are broken: Class... (Ctrl+N), File... (Ctrl+Shift+N), Symbol... (Ctrl+Alt+Shift+N). Just nothing happens when I select these items. Ctrl+N had become kind of my most important shortcut. What could have happened?

Version is 13.1.5; latest Scala plugin. I'm a bit worried that a recent GNOME (desktop manager) update might be involved in this. Is there some special tricks going on in the timing / opening of these particular dialogs? I can see that the current view loses keyboard focus when I press Ctrl+N, so definitely IntelliJ tries to open something. Perhaps of size zero?

Thanks, .h.h.

P.S.: The search-everywhere (magnifying glass icon in top right corner) feature still works, so luckily I can find classe by name using this action. That makes a fix lower priority; I still wonder what the reason is...