Dude I have the same issue and it’s driving me CRAZY!

It’s definitely a problem with Plutonium since this doesn’t happen using the steam version of the game. Seems to be somewhat recent too, so maybe a change they made in the last year broke it.

If you find a fix, please let me know. I’ve been troubleshooting and asking around for weeks with zero progress.

Think I’ll try downloading the Pluto version of the game and see if that still has the issue. Idk if it’s even possible to install older versions of Pluto but I’d like to try it just to see.

Are you launching Pluto from steam by chance?

When the stuttering happens, is it only when you’re moving your mouse?

MrPafXD I have the same issue. I get these messages after loading up a zombies map and at about round 20, it’s like a switch flips.
Suddenly any mouse movement at all will tank the fps by half, even though I’m hitting 125 fps normally. Controller inputs to move the camera don’t affect fps.

You’re using a mod menu I assume?

I’ve discovered that some themes for Project Iconic will cause the issue to manifest immediately upon loading in, and for others it takes until round 20ish.