What is the Sub bonded to? I’d certainly be looking at the potential for wifi interference , particularly in the 5Ghz range, near those two devices…but not restricted there. Any radio signal can be messed with, and not just opinion the frequency in question. At one point, I had a microwave impeding connection, in another case, a neighbor’s new network caused issues. 

If you’re rebooting things, make sure all Sonos devices are powered down while rebooting the router, that way they’ll ask for new IP addresses from the refreshed router. 

Remember, the surrounds are getting a signal from your Arc, not your WiFi. The same with the Sub, if it is bonded to the Arc. 

It may benefit you, if you can, to wire at least one Sonos device to your router directly, just don’t choose a surround speaker or the Sub. The nature of their connection is ‘different’ than most. 

If none of that helps, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

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

Thanks Bruce,

I’ve hardwired the Arc to an Ethernet this evening and reconnected everything (It currently lookslike spaghetti but I’ll deal with that another time!)

On the face of it the components are all linked again and have remained stable for the entire evening. I’ll test again tomorrow,

Thank you  

Sean