I recently changed my wifi password. WHAT A MISTAKE. Something that must be done by thousands of people regularly shouldn't be a complicated issue for Sonos products should it? Every other system and device I own was able to accommodate the change easily. However, sonos products wasted 4+ hours of my life that I will never get back. Self troubleshooting, reading online forums, sonos' own app provided no help. It took one hour just speaking with a customer service agent and physically moving my sonos equipment across the house to hardwire it via the ethernet first, then reconfigure the wifi. Absolute joke.
It seems the only option available is to move your equipment from wherever it is located and plug your devices in individually via ethernet and try to navigate through the app. Good luck.