It's simple, you need to cap your fps more until your gpu have sufficient headroom for OBS. Try cap it to 90fps, after that, try 80fps etc... Don't change your screen hz, only cap fps with in-game frame limiter or RivaTuner.Even with a 2080 Ti and a GTX 1080 at my disposal (NDI user) i feel Nvenc just doesn't work. Trying the highest quality possible at 7k bitrate and it is almost crap compared to x264 faster. I have been streaming at 100 fps for a while and it is even more noticeable there. I'm glad i can choose x264, but the issue is OBS is such a hog for the videocard for the rendering job. As soon as a game takes more than 84% gpu recources, frames are lost due to rendering. There's gotta be a way to lower that somehow. It's pretty much the difference between medium and high settings in game. I have done all the steps to make in game % lower, limit fps at 100, limit hz on screen to 100 etc.