Immense drop in FPS when playing in certain arenas

When I play in certain arenas, such as ATL or OKC, I go from 50 fps to around 39. What is the reason for this?

I didn't have this problem a few days ago...just recently started happening. I didn't change any settings. I updated my video card drivers, and then found out about the issue so I thought I had to revert to my old drivers. After returning to my previous drivers, I still have this issue and cannot figure out how to solve my problem.

Thanks in advance for any help.

Wish I got 39 lmao I get 11

Well, it only happens to my player, for me. So yeah, turn on vsync.