Bug when loading sound file

Hi everyone! I am uploading a few melodies for my experiment. From August to October, I didn't have issues uploading any of my mp3 files. They were 4 piano-only melodies and max 16 seconds. However, starting early November, certain melodies cause my experiment to freeze on a "loading at (50-80%)". I can compile and run the experiment, but I am stuck on that loading screen anytime I change out those 4 melodies (something I need to do in order to show the right sound stimuli). I thought maybe it was a small bug that could be avoided if I picked shorter melodies. I just tried replacing the 4 melodies with 6 new ones necessary for my experiment. They are from the same mp3 stimulus set and range from 9 seconds to 13 seconds. When I compiled my experiment, it was stuck at 81%. I then muted those added lines, and my experiment worked fine again.

I'd greatly appreciate any help with this weird issue. I'm happy to upload an example of my code if that would be useful.