sonos arc ultra stopped working

​@buzz Thanks for the insights on CEC. I will consider this if it does not improve. I read on the subject and it can indeed improve stability to the price of convenience. On my end, I was happy to ditch all remotes and only use the Apple TV remote.

What leads me to think it is a bug with the Arc Ultra is that I have had the setup with an Arc SL for over two years, and I have two different rooms with the same Apple TV 4k model, and I’ve never had any issues. Now switching to the Arc Ultra, which is the only variable in my equation, and I face those recent issues.

Thanks so much @buzz !  The CEC blocker seems to have solved the issue!  I just got it today but after installing that CEC blocker the sound now works.  It no longer is being handled by the apple TV it seems as that has a different volume UI which is fine because it now works with no issues! Also plays atmos content fine so it doesn’t degrade the audio signal.

I placed the CEC blocker on the actual apple TV hdmi cable as instructed in the directions.  So if you need to control multiple devices you will need one per device.  I do everything through the apple TV so one is enough for me.

Anyway it is great that a $15 device seems to have saved the day! Thanks again for the suggestion!

The CEC blocker only somewhat fixed my problem. Basically if the Apple TV or my projector goes to sleep and volume is reset to zero. The good news now is it does recognize the volume buttons so I can turn it back up so I can hear it again but annoying. I wish Sonos would just keep the level that it was when the device sleeps. Honestly I only occasionally watch TV in the evenings so doing this once a day isn’t that bad but if I used the system more it would be really annoying. On the plus side I never have trouble hearing what people are saying like with my previous system and I have never even needed to use the voice enhance feature and it sounds great. Hopefully they will get the bugs worked out eventually. 

Small update: I haven’t installed any CEC blocker yet and I did not have the reported issues for the last two weeks. I believe Sonos has made some updates which makes my new Arc Ultra work as my other Arc SL.

However, it seems that when a new firmware is being pushed, I need to restart the Sonos Arc Ultra for it to find out the paired Era 300 and the paired sub. When the Sonos app shows that the surrounds and / or the sub is missing in my home theater setup, the simplest fix is restart (power off and on).

Sometimes you can work around (prevent, not fix) the lost at update/reboot/power-fail issues by setting static/reserved IP addresses for all Sonos.

Your router’s DHCP settings page should have instructions and it is fairly simple to do.

Once done, power down all Sonos, reboot router and Controller, when both are ready power up the Sonos.

​@Stanley_4 Thanks for the advice. I thought I had done it for all, but it seems one device was still not under DHCP reservation. Something that puzzles me is the number of visible SonosZP under my DHCP registration does not match the total number of devices I have. Could it be that when devices are paired (e.g. two Sonos 5, or an entire home theather) shows up as one device to the router?

In fact, I have 5 SonosZP DHCP reservations, but I have 8 devices in totals, organized into 4 distinct sets / rooms.

I removed my CEC blocker and everything is working great currently. So maybe they finally fixed the issue in an update!

Just received mine three days ago and since shifting from the old Arc I o the Arc Ultra I have these random dropouts more than half the time I turn on the tv or shift source. 
 

Do people still encounter this issue? If not, what resolved it?

​@Jacobdahl Most of my issues are gone with the newest updates:

• I no longer lose the Dolby Atmos as a recognized format between my Apple TV to the Arc Ultra;
• I rarely lose the sub or ERA 300 since I reserved the IP for those devices on my router.

When the sub or ERA 300 disconnect (which happens rarely now), I simply unplug the Arc Ultra for a few seconds, then plug it back on power. It takes a minute or so to restart and then sounds it back to normal.

Thanks ​@Mr Smile. 
 

I had a replacement, since Sonos support could not alleviate the issue. 
 

However, the new one still has the issue. Might need to look out for a new TV to make it work - mine only has an Arc port while I can understand that eArc in other instances does fix the issue for other users.