I was having an issue with the Windows file explorer loading extremely slowly in one particular folder, and I figured out why! It had something to do with the tags on the audio files. It wasn't like that to begin with, it only happened when I tried to batch edit them with the "Properties" menu. I just used Mp3tag instead, cleared all of the tags and then re-added them. Folder works perfectly fine now.

Don't use the Properties menu to edit your music tags, I guess.