Stylesheet is glitching

Stylesheet is glitching. Been doing this for approximately 12 hours now, that I know of?

Screen recording: https://www.dropbox.com/scl/fi/nu0mak059rngosz5gittj/glitching-stylesheet.mp4?rlkey=tme80mrkie3k2z70jsfm0pcfo&st=evqkhpn6&dl=0

Issue: I can't type in the stylesheet without the text bouncing around and creating what I initially typed from anything else I try to type, including just hitting the enter key. Delete and backspace kind of work.

Not recorded, but I've also tried copy/pasting code I'll write externally, but it'll paste it twice on the same like, so...

.korokexample{color:#fff;} will look like .korokexample{color:#fff;}.korokexample{color:#fff;} and I can't delete one of them. It'll delete more than I want it to delete, like removing the } of the first .korokexample. Adding the } doesn't work, as it'll just add all sorts of text as you see in the vide with .ko.

If you need a more thorough video, I can record a longer one.

Edit: I forgot to mention, but Board Templates is fine and works as expected. It's just the theme stylesheet that's wigging.