On Fullscreen,if swtich to another window,when back to game in fullscreen mode,the whole WM will be freezed,I have no choice but to use SIGKILL or restart X11 (even worse,sometimes I need reboot) to make my computer alive again.

Should be a X11 bug,sometimes will broken my gaming experience when using NVIDIA GPU on hybrid GPU laptop,also,I have been experienced this problen in Kwin.