Swami

First video works, then when you go to watch the next it is much going at barely perceptible speed.

wild guess: antivirus software shit the bed.

I wouldn't do a system restore until I knew what was going on.

I would try Malwarebytes first to make sure you didn't pick up some computer clap.

It's a bug in the fucking Bluetooth audio. Just started using it after audio plug has started going bad. What audio has to do with video, I'm not sure, but I found several people with same problem online but no answers.