You meant to ask a question I suppose. What have steps have you taken yourself to get it to work again?

I have switched off completely the Roam and unplugged then replugged the Beam 2. I have also tried to transmit the Bluetooth sound from two different mobile phones. As I have said, it stopped working about a week ago. I have not bought any other electronic equipment that could interfere with the signals. 

Did you try restarting you router and the other speakers?

Does the Roam BT audio stream work by itself (ungrouped)? - if not, then try deleting the BT pairing on the mobile device and setup the pairing again. You could perhaps also switch it over to the other WiFi band. So if it’s currently operating on the 5Ghz band, then perhaps try it on the 2.4Ghz band. I recommend using a ‘fixed’ (non-overlapping) channel for that band, either Ch 1, 6, or 11) and when ‘grouping’ it with the Beam, ensure you add the Beam to the Roam, leaving the Roam as the group co-ordinator. So group things starting with the Roam.

If the problems persist after trying those things, then it maybe best to submit a Sonos system diagnostic report from within the Sonos App, note it’s reference and then contact/chat with Sonos Support Staff via this LINK and see what the Staff can perhaps suggest to resolve the matter.

Yes I have. It's still not working, but hhank you for your help.

The Roam works perfectly with bluetooth sound on its own. I am adding the Beam to the Roam.

It's still not working, but thank you very much for taking the time to help.

Maybe check to see if both the Sonos Roam and Beam are operating on the same wireless access point and the same WiFi band and just see if that perhaps makes a difference.

When I start the music using the S2 app I can share between the Roam to the Beam and vice versa with no problems, I don’t think there is a WIFI issue. To be completely honest, I don’t know how to check to see if they are both on the same WIFI band.

Just check your router, or perhaps look in the Sonos App at the network BSSID, channel etc. and perhaps just ensure the SNR for both devices is above 45dB - see this support link:

https://support.sonos.com/en-us/article/understanding-the-network-details-section-in-the-sonos-app

I recently had the same problem but it was with my Arc. After updating the app and system everything worked fine again. Maybe u have an update pending too? 

It was exactly that. Just had an update on the S2 app and the Roam yesterday, all is working again.

Many thanks for everyone's help.