My entire library has a lot of missing tags for albums and genre and I wanted to update that using the
Identify Track and Update Tags option. Because some songs also had websites as the album or genre tag (the download source), I unchecked the box 'update blank fields only', not knowing it would alter so many files, in a way that I really don't like. The biggest problem is that within entire albums, tracks have been given different Album and Genre tags.
For example, here within the Awake album by Skillet, some songs have been given 'iTunes Session' as album name. The album below by Counting Crows has become one big mess, they all had the album tag 'Films About Ghosts', as you can see on the last song in that screenshot. Now they all seem to have gotten different album names:

Another example, the song Surge by Noisestorm now has EDM LAND as album, while it's actually from the same album Monstercat 017.

And for all those albums that it updated, it actually removed correct Genre tags, and now uses a different hyphen (-), causing a very ugly album tag difference. The bottom ones in this screenshot below are the updated ones, now missing a genre tag:

My hope is that by updating these tags, MusicBee keeps the information in a separate file database, and does not overwrite the ID3 tags in the .mp3 files. If that is true, can I re-use all the previous ID3 tags?
Or have all tags been overwritten and is the old data lost, meaning, there is no solution to this?
UPDATE:
I actually had a backup of all albums on a harddrive, that had the old ID3 tags. I just removed all the updated files from my PC, and placed back in the same location the old ones with the ID3 tags still unupdated. For some reason though, in musicbee, it did not update those tags. Is there a way to force musicbee to re-read the ID3 tags from the files?