Rather than waiting for a Sonos moderator to find time in their moderation duties to investigate, you may want to call Sonos Support directly to discuss it.

Is the Arc wired and have you ‘perhaps’ disabled its WiFi adapter? If so then re-enable it as the un-cabled surrounds talk/communicate directly (ad-hoc connection) with your Arc over their 5Ghz WiFi adapters - if you have not disabled the Arc wireless adapters then power-cycle the Arc and see if that fixes the issue. 

Make sure you have nothing too close to your speakers like a router or WiFi access point and do not cable the surrounds/sub to the LAN.

Consider trying different WiFi/SonosNet channels.

If the above still doesn’t resolve your dropout issues, then It maybe best to submit a further system diagnostic and either note/post it’s reference back here and then contact/chat with Sonos Support Staff via this LINK  and see what the Staff can suggest to resolve the issue.

Hi @breiti 

Thanks for your post!

Although TV audio interruptions aren’t related to networking, I do recommend you connect any one Sonos device (but not a Sub or Surround speaker) to your router (or main node, if you have a mesh WiFi) with an ethernet cable, permanently. This will change the way your whole system connects, which is needed as some speakers are reporting multiple disconnects, including the Arc. Once done, wait a few minutes, then check that all rooms/devices are present in the app, then select Settings » System » Networks » SonosNet Channel » 6. You may also want to try channel 11, but channel 1 (the current setting) is in use by your WiFi. 

As for the reported issue, however, I can see the events in the logs - they are decoding errors, which denote errors in the stream coming from the TV. I first recommend you unplug your TV from power for at least a couple of minutes - this usually clears such issues. If the issue persists, please ensure the HDMI cable is seated correctly, and that you are using the supplied cable.

I hope this helps.

Sonos support told me to turn off dolby atmos. Apparently, it's a known issue and they have no fix at this time.

Hi @mxhawke 

I think you might have been mis-informed. The issue you (and the agent you spoke to) are referring to is this:

It does not match your description (in the case notes) of the issue you are experiencing.

I recommend you also reboot your TV by removing power for at least 2 minutes (and turn Dolby Atmos back on so you can test).

This will be fed back to the agent you spoke with. Apologies for any inconvenience.

I hope this helps.

@Corry P 

Sorry to say he is not alone with this problem. Tried everything and only turning Atmos off will solve the dropouts. Which is kind of wrong with a system tailored to atmos.

AppleTV-SamsungTV-Arc-sub-era300

Hi @mfl1970 

I can’t speak for your system without seeing diagnostics, but in @mxhawke’s case, the issue existed before the stream even reached Sonos - we can’t “iron out” gaps in the audio feed as it arrives.