Try connecting it to your router with an Ethernet cable, temporarily. If you have other Sonos devices, you could factory reset it, before using the ‘Add A Device’ function in the controller, but don’t do that if this is your only Sonos. 

Feel free to call Sonos Support directly to discuss it.

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