I have the app update and it hosed my existing system.  I have an arc, a sub, and two one speakers for rears. The only speaker I can access it the arc now. I cannot add the other speakers back to my system.
 

I reset the rears and they will not add. The app connects to the Sonos network and attempts to add to my network but I get some error to use an ethernet cable. Is this the only solution? It’s not my speed. I have a download speed of 300 Mbps. 

Is there documentation anywhere for this? I didn’t have this issue with the old app (I’m sure you’ve heard this) but seriously, what can I do to fix this?