Not sure if its XWayland but the vision stutters a lot while everything else is smooth. Also X11 seems unusable for some reason on KDE because I get a lot of glitchy artifacts (and Direct Mode seems to be enabled)
Edit: Using an AMD 6750xt with i5-8600k on Arch Linux with KDE Wayland
Seems like the stutters are the reason why async is disabled, turning this on gives me artifacts even on wayland. Anyways, afriend has the same GPU but uses Fedora Gnome instead of Arch Linux KDE so maybe we find a pattern?
At first I had the same Issue as you… till I found out that my DisplayPort cable was half-way plugged in. Took me 2 Hours to find out. Everything acted like everything worked except that the compositor was on Desktop instead in the Headset.