Illustrator extremely slow on one computer. Issues then carry over with file to other computers

So I feel like this is a bit of a unique issue. Never seen anything like this before.

In my office, we have Adobe CC. I have Illustrator 21.1.0 (just updated from 21.0.0). For some time now, files seem to be going extremely slow. To the point where my workflow is affected. What's really interesting, is I can open a file that someone else worked on without any issues, and once i start working on it, the slowdown begins. Then, once i save that file, if anyone else works on it, it will then go slow for them as well.

The issues within the file that slow down are everywhere: eyedropper, aligning objects, moving objects, resizing objects, changing stroke weight, even exporting images.

every. thing. goes incredibly slow. And like I said, once I save the file, if someone else opens it up it will go slow for them too.

I've had IT look at it, and nothing. They reinstall CC and Ai, and nothing.

Please, someone help.