Well I think I found an easy fix after doing some research on the internet.
In settings, go to "gaming" and turn off all the background recording of video and audio. I found recording in "gamebar" and "gamedvr". For me this has fixed the opening video sequences. Haven't had a chance to see if the in game video is fixed.
Credit to
https://www.whatech.com/computer-repairs/blog/435492-fix-games-stuttering-issues-on-windows-10 quote: In Gaming Settings:
On Windows 10, settings for Xbox, Game bar, Game DVR and Game mode are new, but they may also cause serious stuttering in all games with fps drops dramatically.
Turn these settings off to see if it can help improve your gaming performance.
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Well, the first time I started the game, it was fine, but the next time the video is stuttering again. :(