Dolby Atmos, Apple Music sound stops

As far as I’m aware, yes. And my guess is they don’t read you the data, just tell you if they find any issue. If you’re ‘lucky’, one of the moderators here might look up the diagnostic, but again, to my knowledge, won’t ‘send’ you the contents. I suspect/guess there is PID in it, so their lawyers probably are sensitive about that data, due to various laws around the world. And, frankly, I don’t know how much data is in it, it may be too large to really read without training / knowing what you’re looking for or at. 

Oh, and to guess about your particular issue, your brief description points to some (minor) level of wifi interference, not enough to interrupt the stream, but enough to interrupt the commands from your controller to reach the speakers. Since it only happens with Atmos streams, which use maximum bandwidth, it must be just enough to push it over the edge. But I’m guessing, since I don’t have access to your diagnostic data. 

 Called support.  It was WiFi interference.  From where, I have no idea.  The support person rebooted the system, he said, to clear the cache.  That seems odd.  If that’s the case you should be able to clear the cache from the app or at least reboot the system from the app.  LMS-Squeezebox has the capability to do this which does solve glitchy behavior.

 Of course Atmos on Sonos makes a noise at loud gapless track transitions.  Maybe I should give up on listening to classical music in Atmos.

Sorry for your issues. Unfortunate (and contrary to many people’s thoughts), WiFi doesn’t live in isolation, it can be affected by all sorts of things, not only internal to your home, but external as well. They’re merely radio signals, at the end of the day. 

Networks are designed to be constantly changing, in order to use the ‘best’ connection. Sometimes, that can get ‘stuck’ by failures in the router, it’s amongst the many things my ‘go-to’ covers. And likely the ‘cache’ Support was suggesting. 

I don’t tend to listen to any classical Atmos music. All of my classical recordings were made in mono or stereo, but the more data you can provide to CS about this loud sound, the better they can forward it to the engineer who may be assigned to it. 

 The gapless sound is not loud.  The glitch is easily detected when the amplitude is high.  The gapless transition is more like a very, very short gap.  Most of the time when a device or software is not gapless capable there is an obvious muting of the sound between tracks.  With Sonos - Atmos if the passage is low in amplitude the gap is not that apparent particularly with classical music which does not necessarily have a “beat”.  When I tried a Dolby Atmos gapless test that involved a drum beat I could easily tell there was a loss of the rhythm between tracks.

 It’s definitely not the streaming service as it happens with both Apple Music and Amazon Music Unlimited.  Also the same album in stereo has no gapless issues.

Update:

 Wired the Sonos Arc surround system.  Phonos Plus reported WM:0 ( for some bizarre reason the network condition is not shown in S2 any more ).  After wiring I tried the same Atmos album from Apple Music.  Still after some time the system went silent while the app showed it still playing.  After some more time the queue cleared itself and the app switched to a different Sonos device.

 Did talk with support twice: once with wireless diagnostics and once with wired diagnostics.  The first time, while wireless, the rep said it was WiFi interference.  The second rep with a wired config concluded there was an Apple Music issue with Dolby Atmos tracks.

 Just now played the entire album on the Atmos incapable Sonos Port.  Played all the way through.  Still playing the rest of that same Apple Music Atmos playlist.

 Also, unlike the Dolby Atmos version of the album on the Arc, the “Lossless” version of the Apple Music Atmos album on the Atmos incapable Sonos Port is perfectly gapless.