Have you asked Apple? They’re the ones who are reporting that error to Sonos, Sonos is merely displaying it.  

The issue is clearly a Sonos controller code issue since songs that return the issue on the Sonos controller play fine on Sonos speakers when play from other software controllers. And, some songs that are encoded exactly the same will play using the Sonos controller while others will not. And, all songs played fine until version 15.2.  So…

I also have this issue with Spotify I believe it started with 15.6 and also have another issue with at least 4 customer where music is playing on the sonos keep playing but no audio and then audio return after a few minutes and come and go...I also experience this myself at my setup just a few minutes ago was playing a song audio went off of both my speaker check sonos app music still playing..So 15.6 above are full of bugs. 

second update:Since my customer have make me aware of this issue I have experience this like 10 times in less than in an hour. Wow now I feel the pain of my customer this sonos update...

I don’t use Spotify. I have 11,000 songs in iTunes. Some old some new etc. As I was an IT architect at the largest computer OEM in the world, I understand Wi-Fi etc. as much or more than anyone. It’s not a wifi issue in my setup. It’s also not a hardware issue as I have duplicated it on multiple Sonos systems. I love Sonos hardware but too many client complaints over this one issue. I will not switch to another platform as I have purchased over 10k worth of songs. Tried to “redownload” which took 14 hours. Same issues. If I rip a CD of same songs into Apple it plays fine. Also plays fine on Bose and other OEMs. I know of no less than 10 Nashville producers who went away from Sonos as well. I love the idea and used to respect the Sonos engineers but it’s costing them install base. Hope they’ll get serious and fix their app or put Bluetooth in their ARC.

Since my 4 customer who having this issue have spend thousand of dollar in sonos I have spend numerous hours duplicating issue so i can understand better and see how I can help my customers. So far this what I have seen Apple music, pandora, Spotify and airplay are affect by this issue. Services that work ok for me are tune in, local music on pc and amazon Music. I tried to contact sonos right always talking non sense about wifi..I’m on wifi  but my other 4 customer are hardwire so this is no issue with wifi..This is a deeper issue that has been affecting sonos users look like for sometimes. So sad I was planning to buy the arc soundbar but just saw an article about dolbty atmos and Apple tv 4k. and apple tv is what I use the most ..

Here is a video I took about issue with spotify since that what I use the most.

Spotify issue...Amazon music works fine VIDEO

This is why I don’t really go crazy pulling my hair when thing are so obvious last update fix a lot of the issue the I was having with my sonos and customers. 

Well, same playlist plays fine on other platforms with Apple Music.  My Tesla automobile has no problem with streaming Apple Music/playlist, for example.

Only Sonos has experienced this error.  So I chalk it up as Sonos problem, not Apple.    

Or an issue on the server Apple uses to feed Sonos, rather than the server they use to feed their own application.