iTunes seems to corrupt song mp3 files when editing album artwork making them longer by several seconds

When I try to change artwork on particular albums in iTunes, the files are corrupted and seconds are added to the end of the song duration. The time of each song is extended next to the track list (eg. it will read 3:32 instead of 3:27 that was displayed before changing artwork) but upon playback, iTunes gets to the 3:27 mark where the song is supposed to finish, displays that there are 0:05 seconds left and skips this automatically. This wouldn't be a problem but when I go to open the media files from iTunes library with quicktime or any other programme, these extra seconds added on are not skipped and there is added silence throughout the album at the end of each song. Does anyone have a fix for this?

The iTunes version is Version 12.9.5.5

I found this but the thread seems closed: https://discussions.apple.com/thread/8615442