It might be helpful, the next time it happens, to submit a system diagnostic within 10 minutes, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution. I’d certainly expect they might be able to tell you if this squawk is coming from the TV set.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.

A couple of other things, I’d probably check the TV for updates, and then reboot it by unplugging it from the wall for 5 minutes, before plugging it back in.

There have been reported cases, albeit very few, of a cable box turning on to check for updates, which sends a signal to the TV, which passes it on to the Sonos. But generally speaking, your TV shouldn’t be passing any signal when it’s turned off. 

The TV isn’t the culprit. It’s the Sonos. For some reason, it stays on for a while after the system is shut down. We’ve updated everything, turned off Bluetooth, installed new surge protectors, Geek Squad has been out three times and tried everything they can think of.

Thank you for responding.

Have you tried if this happens when any set top boxes are not connected? Or when the TV is taken off the mains?

If it’s the Sonos, the data about that would, I expect, be in the diagnostic you submit, and help point the QA folks, and engineers, to what is causing the issue. 

I only offered a possible explanation that others have experienced, not a definitive answer to your specific, and apparently unique issue. 

Not sure why Bluetooth might be an issue, the Arc only has Bluetooth Low Energy, used for setup, there is no audio capable transmission of Bluetooth on the Arc. 

Do the squawks respond to the Volume control setting?

Does it only happen after watching tv, or after listening to streamed music too? 

It happens only after watching TV. We don’t stream music through it.

What is the source of your TV programming? Which model TV are you using?

By design, the SONOS unit remains ON for a while after the input signal stops. This avoids nuisance delays while the SONOS restarts if there is a brief silence of the input audio.

Do you hear squawks if you reduce the SONOS Volume to zero when you stop viewing TV?

Interesting, Buzz. I’ll have to try that. The Sonos automatically comes on when we turn on TV and the sound switches from the TV to the Sonos. I’ve never had to use the app during normal TV watching. I’ll try that to see if it works.