OK. Saw the capitals.
I think right now you would have to copy some files to your local drive and check them with MP3tag:
one file that looks good in the player
one file that gets only the album name as title.
Check the differences.
First check the tag versions in the file (APE, ID3V2.3, ID3V1) for MP3 files - flacs have always Vorbis comments.
The check if the same tag fields are filled in both files.
Sometimes players have problems grouping files if there is no ALBUMARTIST.