Hey, everyone,
I had the same problem, but I did finally find the problem.
It was DLSS, also turn of Frame Generation if you have 4000 series.
After that, I had a strange error: FPS did not go higher than 107 FPS. It was a bit jittery, so I set it to 90 FPS caps.
No problems ever since! 
PS: Disabling FPS in cutscenes leads to a smoother transition from the loading screen and less jittering.