Airplay to Multiple Speakers for Netflix, PrimeVideo or YouTube TV

This does not seem to be a widespread issue. Do you follow this guide when grouping rooms? https://support.sonos.com/article/group-and-ungroup-rooms

​@ntspgp3 

I also can‘t confirm that issue. I suppose there’s something wrong with airplay on the network if you can’t see some rooms via iOS or macOS airplay control center. Or are you talking about Sonos devices/rooms that do not support airplay themselves and just are grouped with an airplay ready device?

Airplay control center on e. g. iPhone only shows single airplay ready rooms,  not Sonos groups.

But however, I suggest to restart your router and then also your Sonos devices and Apple devices. 
If all your rooms are airplay ready I suggest to start airplay via apple device for all of them instead of grouping via Sonos app. If you want to play the airplay stream on older Sonos devices/rooms not supporting airplay themselves you have to use Sonos app and better do grouping AFTER airplay stream has started. 
If all of that doesn’t help, try grouping just two rooms… if that works there probably will be a limitation in network quality on your network as airplay causes much data traffic. 

Hello Corry,

Well, resetting the App on my IPhone worked magic.  Spotify, Prime Video and Netflix Issues are now capable of streaming to multiple speakers. I would note that using multiple speakers for Netflix appears to require setting from the iPhone rather than via Netflix.  I will have to try this from my MacBook Air as well. But based on the results from my iPhone, this simple task of resetting the Sonos App, resolved the issue. I had no idea that option was there. I would have thought closing the app and/or rebooting the iPhone would have sufficed.  I had also tried rebooting the router earlier, but that did nothing.  

Resetting the Sonos app is the resolution.

Thank you very much!

Hi ​@ntspgp3 

Glad to hear it - thanks for coming back and updating the thread!

You are very welcome!