iTunes "Add Artwork" Glitch Corrupting MP3 Files?

I own a MacBook Pro, running the Mohave OS, and therefore use iTunes to manage my music library. It's just easier that way. That is, it's been easier until recently.

Lately, I've noticed that more than a few albums' worth of MP3s have the final 15-30 seconds of the song looped and tacked onto the end of the file, thus making the MP3s slightly longer than they should be. I've Googled this issue and determined that the problem lies in the "Add Artwork" function in iTunes.

A few details I've noticed regarding this issue:

• If I keep the album art that automatically downloads when the CD finishes importing as MP3s, my files are fine.
• If I add custom scanned album art to the MP3s in iTunes (because iTunes couldn't find a match or I want to create my own art for a particular album) things are still fine.
• However, if I chose to update or replace that manually added, custom album art, my files get corrupted with a repeat of the last 15-30 seconds of the song tacked onto the end of the MP3 file.

The only solution I've found is to trash the whole album in iTunes and re-import the CDs one by one. Needless to say, this glitch is pretty darn annoying, especially for multi-disc box sets.

I still only have one shot to manually add album art, but if I'm careful with my design and meticulous in my choices, I theoretically shouldn't have to do it more than once. Still, sometimes I want to touch up and refine the artwork.

Has anyone else encountered this problem? Have you found a solution? I'm really getting tired of this iTunes glitch.