I would perhaps see if changing the HDMI cable solves the situation… also when you exchange the cable, switch off (not standby) both the TV and Arc for a few minutes to ensure their power has fully drained and then let them setup their HDMI handshake again.

Obviously keep an eye out for any updates for the App too.

Thanks for the advice, I tried a new HDMI cable, but no luck. I think it must be an Apple TV app issue, as no other apps are a problem. 

Hi @Tp10000 

Welcome to the Sonos Community!

I would definitely try a reboot of the TV as @Ken_Griffiths suggested, but I recommend you unplug the TV from power for at least 3 minutes.

As no other apps show the same issue, I would indeed suspect the Apple TV app. I recommend reporting this to Apple and TCL.

Do you have any other HDMI devices connected to your TV? If so, please test with them disconnected. 

A possible way to get audio without rebooting the Arc might be to quickly play music from a streaming service then switch back to the TV again - after starting playback on the TV as you do now with the reboot. This would make the Arc reassess what’s coming through the ARC link, and should be quicker than a reboot.

If you recreate the issue, submit a diagnostic while the Arc is silent and before you reboot it, then reply here with the number given, I’ll see what the Arc thinks is going on.

Hi Cory, thanks for the advice. I tried streaming some music and then switching back to TV, but no luck. I’ve done a diagnostic - number is 2028355552. I have to open the Apple TV app with the Sonos already powered off, and then turn it on whilst the movie is playing, otherwise it crashes the app if I turn it off whilst the movie is playing. 
 

What happens if you perhaps set the Apple TV to output the audio format Dolby Digital 5.1 (or Dolby Atmos, if available) instead of the LPCM multichannel codec? Perhaps see what happens in that situation.

And if you do not hear any audio, rather than powering off anything, if you instead select the ‘TV icon’ on the Services tab in the Sonos App (below the list of music services) whilst you have the Arc room name in focus and showing on the ‘Now Playing’ screen.

Hi @Tp10000 

Thanks for the diagnostics - there’s nothing untoward there, regarding TV at least. Given that other apps behave, it seems the Apple TV app is at fault.

I did spot a possible problem with your Virgin router however - I’m sensitive to it as I had the same issue. If you ever find that client devices drop off the network after exactly 12 hours (especially the Arc - it’ll be less aggressive about getting back online as compared to a device that expects such things, like a smartphone), then I recommend you contact Virgin Media about a replacement due to the router not handling the DHCP lease time properly.

Basically, when a device connects to a router and asks for a unique IP address, the router gives it one, and specifies how long it's valid for. This is called the DHCP lease time. The default setting on Virgin routers is 1 day, or 86,400 seconds. The speakers are reporting that the lease time is 864,000 seconds, or 10 days. This isn't in itself an issue, but the router thinks it's saying 1 day, and it's the discrepancy that causes a problem. After half of the time (12 hours), the router expects the device to get back in touch and confirm it's OK to continue using the IP address. When the device doesn't - because it's waiting another 4.5 days - the router un-assigns the IP address, and the device cannot communicate with the network. 

I've told a few customers about this issue, and had it myself. The customers I've asked to contact Virgin about it never get anywhere with them, so I now recommend affected customer to do the same as I did, which was to buy a 3rd party router, and to only use the Virgin router as a modem (there's a setting for this). If you do replace your router, I'd recommend you spend at least £50 - £70, and go for a known brand, like Netgear, Asus, TP-Link or D-Link. If your WiFi coverage is a little lacking, then there are mesh options from Tenda, Google, Linksys, and others, though these tend to be around the £200 mark.

Until you replace the router, please reboot it every 12 hours.

If you do decide to get a new third-party router, please disconnect anything that's wired into your current router. Log in to the Virgin router setup page (http://192.168.0.1) and switch it into modem mode. The router (or modem, now) will reboot and you'll get a red/orange light at the bottom - that's it ready. Next, connect an ethernet cable going from 1 of the 4 ports on the modem to the individual port on the new router, usually labelled as Internet or WAN. Don't connect to a port labelled LAN on the new router. All of the ethernet cables that used to plug into your Virgin router should be plugged into your new router, using the LAN ports.

Turn on the new router.

Your router manual will come with a card or manual telling you the default IP address it will use. Type this address into your browser and log in using the details on the same card  (you'll need to connect to the new WiFi first). If you want to change the name of your WiFi network, you will be able to do so on the Wireless pages. This won't be strictly necessary, but if you want to avoid reprogramming all of your WiFi devices, you can make the name and password match what they were on the Virgin router exactly.

Although it's out of our scope for support, we do want you to be able to use your Sonos system, so if you need some help, I'm sure we'll be able to assist.

I hope this helps. If you’d like me to confirm this DHCP fault, please submit a diagnostic after the Arc has been on for at least a couple of days. Thanks.