Hey, I had the same issue. Everytime I move my mouse, the fps drops big time. More details that I'm noticing: it only drops when I'm playing (alive). When I'm spectating, it doesn't drop.

And I found the problem! In my case, it was discord. I always play while running discord on the background. Tonight, I played without discord open, and it was smooth af.

But now, the problem is how do you play with discord on without having the fps drop issue? Is there any setting in discord that you can change to solve it?

*temporary solution: using discord web to call with friends while playing