[Karellen]

You state that your music files are mostly WAV. How have you embedded tags in them?

The Music Library completely ignores file and folder names of music files. The Music Library requires embedded tags.

If you have run MusicBrainz Picard on your FLAC files, then your FLAC files are accurate, and it is your WAV files messing up your library.

I deleted the library to start over having removed the various album, but around a dozen albums are stuck

All you need to do is delete your Source, then run a Clean Library. All should be cleared out.

Have a read of the How To Guide... https://kodi.wiki/view/HOW-TO:Create_Music_Library