Did you configure a new SSID and password? If so, before you rush to reset your speakers, change the SSID and password to the same as your old router. If that is not feasible, connect a main speaker to your network/router with an Ethernet cable.

You can also follow the instructions here:

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

Do you have other speakers that are visible? Can you temporarily connect it with Ethernet cable? Have you tried a power cycle?
 

After replacing a router, always reboot everything on the network.