Hi @rrroscoe
Welcome to the Sonos Community!
Does this issue still happen? If not, I’m glad, but I have found the probable cause and we can prevent it from happening again.
The issue is that although the surrounds normally connect directly to the Arc via dedicated 5GHz links, as @John B describes, when they don’t find the Arc they’re instead trying to find Sonosnet on channel 1, but yours is configured to be on channel 11.
To resolve this, please open the Sonos app and verify all rooms are showing - the following steps should not be performed when not all the speakers are connected to the system at large.
Select Settings » System » Network » Change Sonosnet Channel » 1
Wait a few minutes.
Now, change it back to 11 (I can’t tell which channel is best for you, but we’ll assume it’s 11). If you happen to know that your WiFi is on channel 11, channels 1 or 6 will probably be a better choice. If 1 is best, no need to bother changing again.
Once done reply here with another diagnostic number, tagging me, and I’ll double check that all has gone accordingly.
"Common sense is the collection of prejudices acquired by age eighteen." - Albert Einstein
