I haven't been able to find what triggers this, but 10 out of the 11 times this has happened so far were during different battles. The game will still be running, I can click on items, hear weapon/spell effects working, quick save the game etc., but the video will be frozen in place. The only fix is to fully quit the game and reload (Thankfully quicksave works.)
Running this on Stadia. For what it's worth, I have only experienced this while streaming on my PC, not while streaming to Chromecast; but I've played about 90% PC 10% Chromecast, so I'm not sure that's a factor.
