I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it, or post the number here.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, there are more options available beyond just the diagnostic analysis.

Thank you for your guidance. I have done this, and the rep just sent me to Orbi support with little assistance which leads me to ask in this community.

I’d be tempted to try a little CS roulette. It sounds like the rep that responded to you didn’t comprehend the issue.

It's not clear from your post as to whether this is also occurring while watching TV, in addition to the music streaming you mentioned. It is two different data paths, and if it’s only happening on music streaming, it could still be wifi interference. While I haven’t had that particular issue with my DirecTV devices, I have had an HDMI failure on one of the Genie receivers so that they can fail. It might be worth moving the PLAYBAR temporarily further away, or maybe the DirecTV box, just as a test.

However, it’s also possible that it is a duplicate IP address issue with your router, which would show up when either cabled or on WiFi. Try unplugging the PLAYBAR from power, then reboot your router / DHCP hub. Only when the router comes back up should you plug back in the  PLAYBAR. 

You also mentioned an Orbi system, or that they pointed you to some information about Orbi. In general, Sonos doesn’t particularly play well with other mesh networks. It’s not clear one way or the other from your post, but I would recommend that you keep a Sonos speaker (not a Sub or surround speaker) or a BOOST connected to the root hub of the Orbi system so that your Sonos is running on the SonosNet network. 

Thank you again for your suggestions here. I have replicated this issue in both scenarios (playing music from Spotify on my phone, watching TV connected with an optical cable). 
 

I will give the router reset you suggested a try today. I do have an Orbi mesh network, and it is frustrating that I have had this system for a year with no issue and am now just starting to see this behaviour over the last three days. I would hate to throw more money at the problem, but do you feel that if the router reset doesn’t solve that a boost connected directly to the root Hub may solve my issues?

For what it’s worth, I went to Best Buy to get a Sonos Boost to put this issue to bed once and for all. Got home, was all excited for a working system, and then the exact same issue presented itself again within seconds and my Playbar continues to drop.. all other Sonos devices work like a charm, no issue. Did confirm devices are all connected via Boost (WM:0)

aghh I love this system so much but this Playbar is destroying it.

 Adding a BOOST wouldn’t change any IP addresses handed out by your router.  If the PLAYBAR wasn’t powered down while you rebooted the router, it would have retained the questionable IP address.

I’d still recommend a new diagnostic within 10 minutes of it dropping, and try a Sonos rep again.