Hello,
There seems to be a new issue with Gamescope(aside from the black screen after specific commit which is already reported).
With driver 545.xx.xx(both beta and official release)/not sure if it’s related to source 2 games not starting/ but gamescope will not work with borderless or fullscreen under a wayland session(KDE Plasma if it’s relevant), however windowed works just fine.
Additionally gamescope is needed now because 545 while removing the forced vsync in titles that drop framerate or run at ~80fps or less can experience duplication of frames because of the lack of explicit sync, which makes gamescope mandatory in order to avoid that.