I don’t have that router, but you should double check that there’s a 2.4Ghz b/g network turned on. If it’s only using a/c or 5Ghz, Sonos won’t be able to “see” the network. 

I have a similar issue with the XB7.  2.4Ghz is on.

Using the Sonos Boost - no speakers are hardwired. Sonos loses the connection and I can’t stream music.

Greetings folks,

We'd also like to have you follow the following steps to verify that the Xfinity router is not blocking Sonos from accessing the internet.

Navigate to xfinity.com/myxfi

1. Sign in with the customer Xfinity Xfi account
   
   
    
2. Once logged in, click the Devices tab, then click on the Paused Sonos device
   
   
    
3. On the following page, click on the Unpaused Device button
   
   
    
4. Click on Apply Changes to complete the unblocking process of the device
   
    

Once completed, the Sonos Player will be able to connect, register, update, or stream. You may need to reboot the affected Sonos component(s).

None of my Sonos devices show up as paused. I had to reboot Boost and speakers to get it working again. Looking for a permanent fix, I’m losing the connection every few days. 

Are there any Wi-Fi extenders, boosters, or repeaters on this network as well? If so, what are the make and model numbers of those devices?

No extenders or repeaters. 

If none of your Sonos players are showing in the app, you can still submit a diagnostic. Then respond back with the confirmation number.

Would you have a spare Ethernet cable available? If yes, please attempt to swap the cables from your Sonos Boost.

Let me know if that improves anything.

Sebastien, speakers show up in the app so that’s not the issue. Cannot add music to the queue when trying to stream music. I also can’t pull diagnostics when this happens. I’ve tried multiple Ethernet cables with the Boost. 

I am having the same issue since upgrading to S2 app, all of my speakers show up in app, however cannot play any music through them. Tried rebooting xfinity router, no luck.

Hi folks

It appears that your devices have no cloud connection to our servers. Moving forward, we'd like you to give our support team a call.

When doing so, please have a laptop or computer at the ready, as we may wish to do a remote session. You can download the application for the remote session at Sonos Remote Assistance.

Same problem as many on this thread and others. Almost threw my whole new Sonos system out the window - literally - after spending 4 hours on the phone w/ Sonos and Xfinity tech support to no avail and after having set up the system 6 times over the last 24 hours. 

This is what worked in the end! I RETURNED THIS POS XFINITY XB7 MODEM AND HAD THEM GIVE ME AN XB6 MODEM. THEN I DID A HARD RESET ON ALL MY SONOS SPEAKERS AND RE-SET UP THE WHOLE SYSTEM. 

It’s working perfectly now as I sip wine and respond to this thread. Good luck. Happy 2020 with our champagne problems. 

Has anyone found an answer to the issue, I spent over 5 hours on the phone with sonos tech support including escalation and unable to resolve.  Only way mine are working is with one sonos hardwired to router and still I can’t get my Move to show up. Have tried changing security settings on Xfi but to no avail

Here is my experience with the XB7:

I had my system set up a while (Beam, 2 Play:1’s for surround, 2 Play:1’s stereo pair in office and a One in kitchen). Most recent addition about 6 months ago was a Move.  Everything was set up on the original software (S1) with no problems.  A couple months ago, I combined my wifi network to one name and let the devices pick between 2.4 and 5 GHz.  Again everything to work perfectly.

BTW - I’m going to mention other products as it’s relevant to this story.

Last week I had some power outage issues and the gateway restarted numerous times.  This is when I started noticing issues.  All my devices were connected on the network, but my printer would constantly show offline on my MacBook and I lost all the Sonos speakers.  I couldn’t get the speakers back no matter how many times I unplugged them and/or restarted the XB7.  Had an hour long call with Sonos. Was told to go to the router page (10.0.0.1) and enable Managed Sites and Managed Services under Parental Control and click Yes on the Sonos products.  This seemed to work. 

Couple days later, I noticed the Move wasn’t listed in the Sonos app and my printer still was showing offline.  Spent another 90 minutes on the phone with Sonos.  We did a factory reset on the Move and it went through the process except for the last step where it registers with the Sonos cloud. When I turned the speaker off, it would show up on the app with a red dot and say it wasn’t registered and when I turned the Move on, it would disappear from the app (but again, it was listed as a connected device on my network through the Xfi app).

This morning was having issues with my Leviton lights. Couldn’t update their firmware (Move was still not working and the printer was still “offline”.  I decided to experiment and I put my network back to separate bands using the name for the combined network as the name for the 2.4GHz and the same name with “-5g” as the 5Ghz band.  Wouldn’t you know, almost immediately, the Move appeared on the app and said you need to complete the setup.  Within 30 seconds it was done.  My printer was online and I was able to update my Leviton lights.  

The conclusion of all this is that the combined 2.4 and 5GHz network was causing the problem.  Not just with Sonos, but with other products as well.  I am not sure if this is specific to the XB7 or an issue with combined networks in general.  I would have preferred 1 network instead of the 2, but there were too many issues.  So, if you are having this issue, try separating the networks.  Oh, I also turned off the managed sites and managed services (both are back to disabled).

Sorry for the long post, but it shows the issues with Sonos and other products on a combined network with the XB7.