Why do I need to reauthorize my computer?

Just today I tried playing a playlist in Music which contains several albums I purchased more than four years ago. All of the albums in that playlist will play except one, and a pop-up tells me I need to authorize my computer in order to play any of those songs on that album!! What? I have a brand new iMac with an M1 chip, running Mac OS 12.1 Monterey, updated to that latest system just last week. I deauthorized the old iMac and a Mac mini before trading them in to buy this new iMac.

I deleted the album that won't play tonight, then purchased it, thinking I may not have actually bought it (maybe just downloaded it) all those years ago. But I still get the authorization warning.