[2020] ~30 FPS at all times

EDIT Found the solution! Monitor refresh rate has to be a multiple of 60, i.e. 144hz no bueno. That sucks, but oh well!

I have a beefcake of a PC (rtx 2080, ryzen 3700x, etc.), but as soon as I start up the game, the fastest the game will run is at 35 FPS. I have tried:

1. Uninstalling through Steam and reinstalling,
2. Manually deleting the game folder and reinstalling,
3. Installing the game on a separate drive,
4. Verifying the integrity of the game cache.

I'm trying to come back to this game after not playing for a couple of months, but it's making it exceedingly hard to do. I'd like to uninstall the modding stuff, but I can't find where I installed it in the first place - it's just the only thing I can think of that may be causing this (I have no active mods, however.)

Any ideas?

edit: Just installed it on my laptop, and got ~50 FPS, so something is definitely wrong with my install that is persisting between reinstall on my desktop.