Maybe try powering off the router and speakers & bring them back online (one at a time) in this order:

• Modem/Router
• Wired Products
• Wireless Products, (nearest first)

 and perhaps try again and see if that sorts it…

Also, all the Sonos speakers need to be running the same operating system, either S1 or S2. You can’t group one with the other.

A bit more info on what you are doing and what is happening would give us a better chance of helping.

Thanks for the above. This seems to have fixed it.
 

@Lee84, 

The likely cause, I suspect, is the router getting confused when handing out IP addresses to products on your network. It might be worth reserving (setting static) the Sonos IP addresses in the routers configuration pages, as that will mean they’ll get the same IP address allocated to them whenever they, or the network, are rebooted. It should stop the issue from ever happening again.

See your router manual to set the addresses static.

Hope that helps too.