Any chance you’re running a mesh network? It could be that one phone is connecting to one subnet, and the “new” phone is connecting to a different subnet. 

Is that S1 or S2 that you’re showing? 

Yes, it's going via a mesh, so likely it can be connected to a different subnet...not sure how I can check/change.

Using s2

Try turning off all the mesh “extender” pucks, at least temporarily. Make sure your new phone is logged in to the wifi system, and try the Sonos app again.

Which mesh network are you running?

Will try in the morning. Thanks for your responses, I think you are along the right lines on this.

Its a Huawei Ax3000, not the greatest interface.

I have ordered an eero which should replace the Huawei

Switched off the extender nodes, ran only the primary but still didn't connect unfortunately 

Hmmm. Then I think you’d be better off calling Sonos Support directly to discuss it.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.

Fingers crossed, seems like the new mesh has resolved it. No idea what setting or conflict was blocking it but it's worked with the new set.

Thanks for all your help

Having the same issue on an iPhone. Device shows as not connected, unable to update, unable to Trueplay. The best solution I’ve found is to reset the application, not login to my account and control that way.

Unfortunately, using the app this way renders connecting to other services, including Sonos HD useless and unavailable but at least I can see my system and control this way. 

I’m happy to see Apple has brought back their HomePods because the dependency of the App for updates and some control of the Sonos system is very frustrating; it’s the thing keeping me from investing more into Sonos.

Not really sure what ‘Sonos HD’ is, but it sure sounds like you need to call Sonos support for assistance in working through your local network issues.