Not sure if you have seen the link below or tried from the Sonos support. Community might need more details about your network setup. New router or modem running on a mesh system?? Are your Sonos devices on the most current firmware and app on the most current app. Are you on iOS or Android? 

https://support.sonos.com/en-us/article/connect-sonos-to-a-new-router-or-wi-fi-network?language=en_US

When you replace a router, the easiest thing to do would be to set the SSID and password the same as the old router. This would allow most devices to automatically reconnect to your network.

For those devices that do not automatically connect, you may need to reboot them so that the get a new IP address.