Why is the editor super buggy right now?

I’m trying to re-do all the front-end challenges, and on a lot of them, I can only go forward by 3 or 4 spaces in a line before it automatically moves to the next line and won’t let me edit code.
I’m getting pretty frustrated with it.
The mouse cursor doesn’t help, using Chrome instead of Firefox doesn’t help, restarting the browser doesn’t work, refreshing the page doesn’t work.
It literally refuses to allow me to move forward by 3 or 4 spaces before it just skips down a line.