Sorry, I wasn't clear - just mentioning that I'm using Sway, but it's not the problem. The problem was with apps running in XWayland, e.g. Gimp, Firefox, Spotify, Slack, gnome apps, etc

Ah, gotcha. The Wayland situation in Firefox has been changing for every major release BTW. Been running it in native Wayland since recently and so far it’s mostly been good and stable. Still the occasional crash or popup glitch but since ~v94 it already feels worth it.