Major FPS drop in 4.18 = bug?

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…?

I created a new tread with this problem here: https://answers.unrealengine.com/questions/1012889/huge-fps-drop-in-editor-after-opening-blueprint-wi.html