Here's the thing:

I downloaded some live concerts of a website, and there's 15 tracks in both of them. So I fix the file names for the first concert with track numbers, and batch tag the track number a title fields with Tag Studio, and it got everything except for the last song. The rest had no problem. The last wouldn't let me write anything to it. I then try the second concert, doing the exact same thing, and the exact same thing happened. 15 songs, the first 14 were fine, the last one wouldn't let me write anything to it. Could this be a bug? I'll try doing it with more folders.

*edit*
okay, I tried it a third time, and the exact same thing happened.