I'll try this when I get home.Hello guys, so it seems that the nvidia driver is the problem, 419.35. I basically updated OBS and Nvidia driver at the same time and I had the same problem like you. I did a few tests with some older OBS versions , lowered quality and all but still the same problem. So I downloaded nvidia driver 419.17 and everything is working perfectly fine now. Im using OBS 23 with the Nvenc New Settings : VBR 40K to 60k , Max Quality and both those new boxes ticked.
I have a RTX 2080 and obs uses around 25%.
Hope this helps,