Actually I had the same problems on some maps, only got screen for 1 map though.
Like told before, it says in the top left corner that my fps are at 60 like always, it feels like 20 though with all the stuttering.
It was on this map (forgot the name :3)It got worse the closer I got to the mountain at the spawn seen in the screenshot.(click to show/hide)
Funny thing is that if I'm close to this mountain and turn my back to it it's fine, but if I get close to it AND look at it my fps drop like crazy.
i get this too. people say this is because i dont use wse2, but when i do, the frame rate is tearing as fk.
kinda double sided blade.
Have you tried setting the maximum frames to 59?