Aswell as rebooting the router, also power off ALL your Sonos devices for 20s, or so, that usually gets rid of any old ‘no-longer-used’ devices.

I moved into an apartment that uses a Wi-Fi that everyone shares. My Sonos system will connect from time to time but never will steadily stay paired for all rooms. I spoke to support and she mentioned turning off the router which I don’t have access to so, anything with rebooting that Isidro likely out of the picture. Additionally, I’ve tried using an Ethernet cable to my beam in order to get it to work but no luck. 
 

Has anybody had the same issues with a community Wi-Fi and how did you get around it? 

Some users who have posted in this forum previously, have got around their community WiFi woes by installing their own router/travel router, so maybe try that and regain full control of your LAN subnet - but you still may face some restrictions, if any have been put in place by the community WiFi setup.