Ah, yes. I haven't done any testing under wayland at all. I've heard mixed things about Qt5's support for it, but Qt6 is supposed to support it well. I'm hoping to do a fair amount of testing under wayland in preparation for moving to Qt6.

Using XWayland *may* work for ShowEQ but I haven't tried it.

Or if you really want to play guinea pig, you could try it under Wayland proper. You'll need to have whatever package provides the wayland platform plugin(s) but you can specify what platform driver to use when running ShowEQ by setting the QT_QPA_PLATFORM environment variable.