I reported the problem here a couple of weeks ago :
Today, I added one album (A 45 single with 2 tracks) which set off a full scan of the library, and repeated the scan several times. It eventually quit, and about 5 minutes later started all over again. During the scan, the network activity jumps up:
I think the server is trying to match and re-match any albums that are unmatched. I have hundreds in my relatively small library of about 2000 albums, because MusicBrainz doesn’t have an entry for them. (ripped old vinyl albums and 45’s from the 60’s and 70’s)
I am at the point where I hate even considering adding new music because of this apparent no-problem, non-existent glitch.