See https://www.mail-archive.com/lyx-devel@lists.lyx.org/msg219735.html
* Compiling LyX 2.4 on MacOS with Qt6 makes currently LyX unresponsive to
Control-Command keyboard shortcuts (bug #12641).
+* Gnome environments defaulting to Wayland + mutter compositor might be missing
+ proper window decorations. This is a generic problem which can be for Qt-based
+ applications (including LyX) alleviated by setting QT_QPA_PLATFORMTHEME=gnome
+ environment prior to running LyX.
+
* For others see http://www.lyx.org/trac/wiki/BugTrackerHome