Assuming you don’t have a routine set with either Alexa or Google voice assistant have you tried connecting the Beam to another TV (if that is an option) to see if the issue occurs?

What happens if you uncable the Apple TV from the Sony TV? My thoughts are to try to eliminate things one at a time and starting with disconnecting that device, will at least begin to narrow down your search.

Thanks for your reply! I checked this after your response last night: I did have routines but I disabled them all, it still happened :( 

No other TV to check with, unfortunatley!

Thanks Ken! I will try this tonight, I’ll watch Netflix straight from the TV app rather than Apple TV (with the Apple TV disconnected and feed back!

Update 1

Sonos are still circling on the idea I need to reboot my router to fix this issue. It restarts every night at 1am anyway, and I’ve tried it several times and it does not resolve the issue. 

Sonos unwilling to move to the next step of troubleshooting til after I’ve restarted my router an hour before the issue, then the issue will occur at 9pm, and I’ll submit a diagnostic straight after from the Sonos App. 

Update 2 

Obviously it has happened again. I have tried what you suggested Ken_Griffiths - I disconnected my Apple TV, launched Netflix App on my TV, so the only thing connected is the Sonos Beam to TV via HDMI / ARC.

• I rebooted my router as Sonos requested.
• I have submitted diagnostics to Sonos as requested.

I’m still frustrated that Sonos think this is a Network issue. It’s clearly not. A physical HDMI cable between 2 devices. I could essentially disconnect my TV and my Sonos from any form of network and the issue would still prevail. Keyboard warrior is coming out in my frustration 

@lifeofbryley Have you tried disconnecting your TV from the network?

It’s unusual to say the least, just the fact it happens at the exact same time every night, perhaps suggests it’s something ‘scheduled’ and it will be interesting to see what your diagnostic report eventually reveals.

Can’t say I’ve ever seen a similar issue mentioned on the forum here, but at least you have begun to narrow things down slightly by disconnecting the Apple TV. 

I take it that you don’t use any 3rd Party Sonos Apps that use the Sonos API like:

• IFTTT
• SORO
• Spotify Connect

Also… Anything that might be scheduled to switch on around the Home at 9pm, that might interrupt/interfere the local power supply, central heating, cameras, timer plugs, smart-lights etc?

I’m mildly concerned about a router that restarts every night at 1 AM. Do you know why this occurs?

It might point to something that could be disconnecting everything at 9PM. For instance, if it’s an IFTT process, or similar, there could be a similar process sending some sort of interrupt to the Beam causing it to disconnect, or to the TV, causing that to temporarily stop sending an audio signal out via ARC to the Beam. 

It may not be a direct network issue, I’d agree, but there are tangential things that might be contributing to the problem.  And if it is something pausing the network for a moment, then your Apple TV or Netflix app on the TV would be affected, and stop sending a signal to the Beam as well. 

@lifeofbryley

Personally, I’m inclined to agree with Sonos tech support that the issue is network related. Others have pointed toward connected devices and/or streaming services as a possible cause. Not to say it isn’t possible but I can’t without reservation wholly support that supposition.

Mind you … I’m no expert nor definitive word on such things by any stretch of the imagination. However, in the words of the late Rod Serling “I offer this for your consideration” have you considered a parental control routine that may be active in your routers admin settings to dis-allow network connectivity at 9PM every evening. Granted the duration is Incredibly short… but who knows until you investigate. IMO it’s worth a look.

Could this be electricity related? A short power outage or signal sent through the power network?

Update 3

I spoke with Sonos again, I think I got sent through to their senior support team.

• They’ve looked at the diagnostics I submitted straight after it happened; there’s no network issue occurring and no power blip. 
• They have said there’s possibly a signal issue from the TV but can’t confirm. They’ve asked me to speak to Sony and if they can’t see anything, to go back to Sonos to escalate it to their dev team to do some bug investigation.

To answer everyone else (thank you for your comments)

• No parental controls in play
• No IFTT / automations etc in play
• I do have Spotify Connect but nothing that’s triggering anything from what I can tell
• No other devices are on any schedule for 9pm
• No other power related issues
• Strange it’s only started happening over the last few weeks, I can’t think of anything that happened around the time it started - no new devices etc on the network.
• For info: when the speaker cuts out and then goes to the TV and back, the sound never stops, just changes where it comes from.

I’ve now turned off the WiFi on the Sony TV as per @GuitarSuperstar suggestion, we’ll see how it goes tonight!

For info, here’s the video of what’s happening - you’re welcome Office fans :)

It looks like something is momentarily stealing the HDMI-CEC focus for a second or so, looking at that video - but you disconnected your only HDMI connected device, which you mentioned, which is the Apple TV, so it’s still quite baffling. So there are definitely no other HDMI connected devices to the TV, such as a Cable TV box etc?

Unless it’s some kind of CEC refresh that the TV does once a day, but what a strange time of day to do that anyway. 

My only other thought is that the TV is perhaps renewing its ‘leased’ IP address and if disconnecting it from the network resolves the issue, then try increasing the routers DHCP servers IP address leasing-period from 24 hours to some greater time value and see what effect that may have on the issue.

See my post here and see if it is related to your problem

Update 4 - Final Update

Well, I’m eating my words, annoyed at myself but finally have a solution. Though, the logic of it still baffles me.

Last night I set things up for tonight’s test: 

• I disconnected my TV from the Wi-Fi
• I took on board all your suggestions, I had a Tapo wifi plug upstairs that was powering an extension lead to my desk; including 2 Sonos Bookcase speakers. This Tapo plug was set to power off at 9pm every night… can you see where this is going? So I set this plug to go off at 9:05pm tonight.

Guess what happened? The audio interruption happened at 9:05pm on the dot.

• Why turning off speakers in another part of the house causes a physical audio blip, I don’t understand.
• I am putting my hands up and admitting I was wrong to question the whole network thought process. It doesn’t make sense to me, but, it’s obviously what’s happening.

I would like to caveat that I have the same plugs in several rooms around the house, and all on timers for various things. None of them have the same interference issue so it’s lead my to believe that 2 Sonos speakers disconnecting from the network at 9pm is causing this blip. Why it interferes with a HDMI connection, I can’t understand - to my mind Sonos should address this, as it should be independent of any networking capabilities.

Any way, with egg on my face - but happy to have resolved it, I’m calling time on this one!

Thanks all for your continued thoughts and help!

It’s not a good idea to have your Sonos speakers disconnected from power on a daily basis.  This isn’t a recommended practice, so I can’t see Sons making changes that support that.

I would definitely put these on a different plug.  At the very least, you would confirm that it’s the speakers leaving the network (due to no power) that is causing the blip and not some sort of electrical issue that is causing the TV to drop the connection.