I have this exact same problem
I am having this problem as well. That youtube video is basically EXACTLY how my game was the first time I played it.
I've got all my drivers up to date and have subsequently been starting new games and creating characters to see if the problem will go away. (I do not want to start playing in earnest until this is functioning properly)
On subsequent new games I've gotten the problem to lessen, I've even managed to get through the intro cutscenes without any of these cutscene glitches, but I'll still see similar problems in later dialogue/cutscenes.
The problem seems consistent but when it strikes is rather random but frequent.
I've also noticed unusually random load times and wonder if the two are related.
Aside from that I have everything set on Ultra and the game plays smooth and fine
