This is an odd one.
For me, I had a similar issue (almost like you described), but it was because of PulseAudio.
Just to rule it out, restart the puleaudio service when this happens, and see if it “continues” to play the video or unfreeze.
systemctl --user restart pulseaudio
In my case, only the video was affected. The rest of my system was fine (no crash, no hang, no freeze).
Other than that, you can also do two other things, even both at once:
- Remove the
xf86-video-intel package
and any custom .conf files you might have created under/etc/X11/
- Install and boot into LTS kernel 5.15