So you’re always going to get ones that drop off because there is a change in music rights. Like the Latin Simone one, It doesn’t even show up when I search that album so my guess is it’s on an old or different version of that album. The Play It Be It one doesn’t show up either. So I think the rights are gone there. However, the fix is actually what you already mentioned. Well I mean it’s a workaround I figured out, it’s not a fix. For whatever reason, if you have those old songs tied to your Apple ID it can’t play that song anymore even if you pull the correct version in.
So here is the fix - and please test this on a couple songs with a test album first so you understand the steps and don’t blow up your library.
1) Send the playlist to another device, I used my wife’s but it has to be a device that doesn’t have you signed or signed in with a different Apple ID so you can actually send the playlist.
2) On the second device, the songs will automatically map to a current version of that song. I have no idea why we can’t just refresh the mapping on a device but you can’t.
3) Duplicate that playlist on the second device. While in the playlist hit the three dots in the upper right, click add to playlist, name the new playlist and create it.
4) Delete bad songs on the first device.
5) Send the playlist back to device one from device two. This will remap all the songs to whatever version is out there now and ignore the old mapping.
You’ll want to duplicate all the playlists first so you don’t lose songs on multiple playlists. Because as soon as you delete the songs they will drop from the playlist. Since they aren’t in your library. You can also remove step 3, but that’s kinda risky if something maps weird. It’s better to just duplicate it.
I would also make a playlist with all your songs to remap all the the other songs not in a playlist and do the same thing.
I think the real question is why there isn’t an option to refresh mapping on a song within Apple Music or iTunes.
I’m still working with Apple Support. My thought is a lot of those albums they dropped rights on because there is a new version, the rest of the mess is unintended consequences of them not realizing song from pre Apple Music that got uploaded are causing issues with adding the same song back in.