Hi @KeithSloan
Powerline extenders may work with Sonos, but it can be a bit hit-and-miss - as a result, they are not officially supported. I recommend trying things with the extender turned off and the speaker located somewhere that the main WiFi can be picked up, and working from there.
If the Powerline must be used, it should help to ensure that the device running the Sonos app is also connected to the same extender. Rebooting the extender (and the device it connects to on the other end of the Powerline link) may also help.
I do, however, recommend you get in touch with our technical support team who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports - please be aware, however, that as Powerline is not supported, they are unlikely to assist with this. They will be happy to assist once the Powerline has been removed, however.
I hope this helps.
"Common sense is the collection of prejudices acquired by age eighteen." - Albert Einstein