Power down all Sonos, reboot controller device and router, power up the Sonos.

And, if that doesn’t help, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here, they get sensitive about GDPR.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

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

Is Wi-Fi disabled on the soundbar (https://support.sonos.com/en-us/article/disable-or-enable-wi-fi-on-your-sonos-products)?  If so, you aren’t going to get any sound via the surrounds.  The soundbar needs Wi-Fi turned on in order to establish the private network connection to the surrounds and/or sub.  

Wifi is enabled/on. I’ve restarted everything. That showed a new problem because on satellite didn’t reconnect with the sound bar. 
 

I’ll try the process again and then use the diagnostic suggestion

​@James8668x 

Did you remove the speakers from the Beam via the app before trying to connect them to the Arc? Even if the  Beam shows no surrounds connected you still have to remove them from the Beam via the app removal process. 

When you remove surrounds via the app they will revert back to their individual room name. At that point they can be added to the Arc via the app.

Resolved. Was an issue with WiFi settings and clever sub networks set by the router. I plugged an Ethernet cable in to the Arc and turned off the clever router settings. 

​@James8668x 

Glad you resolved your issue. 

Just so you fully understand…..what you did was remove the Arc from your home Wi-Fi by connecting it to your router via Ethernet. At that posit turning-off WiFi band steering or as you call it “clever router settings” really no longer affected your Arc.  Alhough the feature may have steered other WiFi capable products in your home to a particular band. As far as the sub is concerned it really had nothing to do with your issue as it receives instructions from the Arc via its proprietary 5Ghz band; as do satellites speakers used as surrounds with the Arc.

Full disclosure...I have Band Steering turned off on my router as well. However, none of my 31 Sonos units are wired via Ethernet to my router.