I didn’t mention this in my post-run report today, but I had planned to listen to the R.E.M. album Accelerate on my run. It is a very good album for running, as the title might indicate.
Except it wasn’t there in Apple Music when I searched by (Downloaded) Albums on my iPhone 12:

Also, I have no idea why Abbey Road is listed twice.
I checked under (Downloaded) Artists:

And it turns out two R.E.M. albums are missing, Accelerate (2008) and Collapse Into Now (2011). These are albums I own, not just streaming ones I’ve downloaded. And they are albums I have listened to many times on my iPhone (Accelerate, in particular). I have not touched my music library in any way. Where did they go? Only Apple knows. Actually, Apple probably doesn’t know. But the bigger question is: Why is Apple disappearing albums I’ve actually purchased? It’s like the company is actively trying to push me away.
And guess what? It’s working! I am starting a trial of Deezer.