My Sonos sub Gen 3 has decided to stop working on my surround sound system. I have the Arc, 2x ears 300 and the sub. I have reset everything. Disconnect and set the system back up again. If I remove the sub and connect to my 2x one SL system upstairs the sub works fine. Otherwise once connected back to my tv surround sound I get no sound and a green slow flashing light that indicates new product? 
 

Moderator Edit - removed diagnostics number.