Hope this helps..
Was suffering audio dropouts on my Sonos surround Play 1 speakers listening to music. Sonos support stated that it was my network causing the issues. I have been trying a number of workarounds trying to eliminate this problem. I tried converting the Playbar and all the surrounds and the sub to wired ethernet connections (GigE connections) and still had dropouts.
I never considered that the ethernet cable connected to the second port on the Playbar to the TV as a passthrough would cause the dropouts (especially when the Sony TV was off and there was an optical cable from the TV to the Playbar) but this was the culprit. The optical cable is still connected to the TV.
I disconnected that ethernet cable from the Playbar to the TV and since then haven’t experienced one dropout in over a week with many hours of listening (where before I could go maybe 5 minutes). I have since disconnected the ethernet from the surrounds and the sub and still no dropouts (so my wireless was fine as well).
I wish I hadn’t suffered for years with this issue but at least it is now resolved. I would avoid connecting anything to the second ethernet port on the Playbar whether you think it is being used or not.
Now back to enjoying music ...