So far I've tried reinstalling windows twice (along with reinstalling drivers and game, obviously).I have exactly the same rig as you and dont get this. Probably an Nvidia driver thing
461.40 here and no problems. Also, I dont use reflex, Geforce Experience or any FPS overlays like Riva tuner stats server
Ryzen 5800x (stock)
RTX3080 (stock)
32GB 3800MHz CL14 (teamgroup 8 pack)
MSI X570 Unify
By far the best feature of this game is player death mic. I was on a 9am Plunder game and killed someone in the sky who came back for his revenge. In an early morning German accent Terminator voice I heard "F U" Made me chuckle the whole game
On my recent windows reinstall I installed 457.30 drivers instead of the most recent ones and the problem still persists...
At least you confirmed to me that it's definitely not how the graphics are supposed to be.
Problem is still there with all the things you mentioned disabled (although I use all of them normally).