I have been an iTunes Match for several years, since shortly after they introduced the service. Recently I noticed that entire albums were missing off my phone, or weirder still, that some albums would have two or three tracks present and the rest missing.
After checking that I did not have “Only Offline Music” selected, I did the obvious: I logged out of my Apple ID account and logged back in. A lot more music disappeared. Now roughly 90% of my music is missing.
Some artists are entirely present, some have taken huge hits, and a lot have exactly one song each.
I have also deauthorized my main computer (which has all my music) and reauthorized it in the hopes that would force a resync, but no such luck.
I should also mention that I never signed up for Apple Music, not even the free trial. I know there were some problems there, but that’s not the cause of my woes.
So what is going on here?