I’ve got Apple music as a service. Some of my tracks are randomly greyed out now in playlists. They are fully available in Apple Music and play fine in iTunes from the same playlist. I do NOT have any parental crap turned on inside the Sonos app. I’ve dropped and re-added the Apple Music service in Sonos.
Still greyed out tracks. My brother has a similar system and is noticing the same crap.
Any solution?
Just added Apple Music this week - this is now happening to some tracks in my library.
Not magically fixed 
So I have this problem too and not sure its a Sonos issue vs an Apple one. I actually have the exact same problem between Apple Music on my iPhone and on my iMac. So today I added an album to my Apple Music library on my phone. 3 tracks are greyed out on the Sonos app. The same three tracks are also now greyed out in Apple Music on my iMac. If I view the album on Apple Music on the iMac (not via the library) everything shows up and plays just fine. Not sure when this started happening exactly but it was with one of the recent iOS updates or maybe Big Sur on the Mac.
update: deleting the album from the library on my iMac and readding fixes the problem. added another album and boom 3 tracks greyed out. delete/readd and they show up again.
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