My router continues to communicate with the various PLAY:1s I have. Seems odd that when you wire a device directly to your router, it still isn’t seen. Did you perchance change any other settings, such as security settings, other than the SSID? Like changing to WPA3?

Have you called Sonos Support directly to discuss it?

Thanks for the reply Bruce. I know they're first generation Sonos speakers and was wondering whether it had anything to do with the app problems? I will contact support though. 

I wouldn’t think so, no. But support would be able to tell you better than I would.