Same here. RTX2080.
No Sonic Suite installed or other audio stuff. No Experience installed. G-Sync off is even worse for me, G-Sync in fullscreen or window mode make no difference.
I rolled back to 461.40 - it felt like the last stable one until it started - no change.
It just occurs with open UE projects. Any game is smooth as ever, no black screen glitches as I get in the engine.
Will roll back to 388 I guess…?