Where are your files located?
Locally? On a NAS? External USB-HDD?
What kind of tracks do you use? MP3? FLAC? WAV?
If you use FLAC files, it could be that one of the latest Mp3tag changes could be the reason:
`[2024-01-23] CHG: optimization function for FLAC files now preserves a small padding block to increase performance for possible tag modifications.