Was the router ‘off’, when you rebooted the CONNECT:AMP?

I’d suspect some IP address issue, but there isn’t enough data to be more than a guess. You could 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.

Thanks for the quick reply, Airgetlam. No, I rebooted the router first then reconnected the amps.

Wasn’t sure, so it was worth asking The router should really be off when you rebooted, otherwise it might be hanging on to an old IP address. 

I’d definitely go the diagnostic route. 

If calling support is difficult you might pursue the IP address issues first since you can do that yourself.

Go to your router's DHCP Settings page and set static / reserved IP addresses for all Sonos. Power all Sonos down, reboot router and controller then power up the Sonos.

I’ll give that a try, thanks. When I’m on the DHCP settings page, do I assign a specific IP address to the Connect:Amp? Thanks again.

As long as the address is unique and within the address range managed by the DHCP server, it doesn’t matter if you or the server assigns the SONOS addresses. I reserve addresses for all regular network clients.

I assign addresses so the Sonos sort pretty on the DHCP page, mine by Room.

Are you running S2 on your C:A? They really struggle on S2 these days.

Yes, I’ve got S2. It was pretty buggy when I first started using it, but tbh I haven’t had many issues in the last year or so.