Lag spikes with new update

[Legionary]

Was really excited to get into the new update introducing plague territory but now I am having massive lag spikes and sometimes even crashes in the middle of the game. I was able to run it on ultra ever since I bought the game, but with this update I can barley play on Medium/Low settings without something going wrong: Driving, 10+ zombies, and even at base's upgrading and gearing up or unloading and more. Is their a way to fix this?

Edit: System specs are
CPU: I5 3.20 Ghz
RAM: 8GB
GPU: Radeon rx 570

[Project88]

I have the same problem. I'm IN RAGE :(