@fmuellner could you have another look at this and see if you'd like to push it to stable?
Could the other two be pushed to stable? It is only mutter that is affected by that and 42.1 fixes bugs in the others too
This has been fixed for gtk4 applications (https://gitlab.gnome.org/GNOME/mutter/-/issues/2261).
Bear in mind that not updating GNOME shell to 42.1 keeps this annoying bug in (https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/4919)