Created attachment 115079 [details] audio cds kcm under Wayland Neon dev unstable here... See the screenshots. "Audio CDs" kcm started via the apps launcher under X11 shows the buttons on bottom. The same buttons are hidden when the KCM runs under Wayland. The same happens with the following KCMs: energy saving cookies window behavior kscreen
Created attachment 115080 [details] audio cds kcm under X11
I forgot to say that the buttons appear when the window is maximized.
SizeHint too large, maybe?
One of the things that comes to mind is checking if QDesktopWidget::availableGeometry properly accounts for struts/space reserved for panels in wayland session. Not sure when I'll be able to check this myself because I can't run kwin_wayland on my desktop.
Related to/duplicate of https://bugs.kde.org/show_bug.cgi?id=366632
Definitely a duplicate. Nice find, Alexander! *** This bug has been marked as a duplicate of bug 366632 ***