SUMMARY Second level menus inaccessible in Wayland session. STEPS TO REPRODUCE 1. Start a Plasma(Wayland) session 2. Open Kmail 3. Attempt to open a second-level menu (e.g., View --> Message List --> Sorting) OBSERVED RESULT Second level menu disappears when mouse pointer hovers over it. EXPECTED RESULT Second level menu should let me make a selection. SOFTWARE/OS VERSIONS Windows: macOS: (available in the Info Center app, or by running `kinfo` in a terminal window) Linux/KDE Plasma: kernel 6.12.31 KDE Plasma Version: 6.3.5 KDE Frameworks Version: 6.13.0 Qt Version: 6.9.1 ADDITIONAL INFORMATION I recently got Wayland working tolerably well by installing Nvidia's prooprietary video driver. Before I did that, nothing worked ... the mouse pointer jumped all over the screen when Plasma came up under Wayland. Now I've got most KDE apps working OK with Wayland. But the menus aren't working in Kmail. Dolphin works. Okular works. Kate works. But not Kmail.
I recompiled the Nvidia video drivers and specified the "open_source" option. This resolved most of my problems with second-level menus. So I'm closing this out.