Apple Broke Dolby Digital 5.1 Output on Apple TV 4K

Having the same issue with first gen ATV 4K, a Sony TV and Sonos beam connected via ARC. Everything worked fine before tvOS 18.

3rd gen ATV 4K connected through Samsung tv and a Sonos Arc not having this issue.

outputting to the Beam via the TV’s apps nets 5.1 again so clearly it’s the ATV.

@llee: I'm not sure that's true? You fill out the feedback form and then on your Apple TV you hold down play/pause and volume down for 6 seconds, the ATV generates a debug file and then you just airdrop it to your Mac or iPhone (I think, might be Mac only). The Mac doesn't need to be enrolled; I know mine isn't.

I am experiencing the same issue after the tvOS 18 update. I contacted Apple Support and opened a case. They informed me that the issue will be escalated to the backend engineering team and addressed in the next tvOS update, which is expected to be released in a couple of weeks.

I also shared this discussion forum link with them so they can read posts from people experiencing the same issue.

I am using HDMI de-embedder out to an Integra Surround Sound Receiver.

I have dolby 5.1 via the optical from the extractor on a model A1842. I disconnect it and then connect a model A2169 to the exact same cables and lose 5.1 (only get stereo).

Both units on TVOS 17.6.1

What's crazy is I have 4 Apple TVs from the latest to the earlies gen. All of them were 18.0 and the newest ATV was feeding an Atmos system. I had no Atmos all of a sudden and some of the apps were reporting either stereo of spacial audio instead of Atmos. I forget exactly what I did after that I did a factory reset and went through the painstaking task of entering all the passwords again. Then I noticed all my Apple TVs had 18.0 and the newest one was 18.1 and Atmos was now working again. This was weeks ago. And now I see the 18.1 is just now coming to some people. I wonder if it had to do with my factory reset?

I updated to the not named and 5.1 only works if I choose Change Format in 5.1. But if I do that, I lose Atmos.

If I turn Change Format off, it seems like it "sticks" for a bit but only on the thing I was watching. If I choose another movie or show from the same app, it's back in stereo. And I don't think it even "sticks" permanently to the thing I originally "unstuck." If that makes sense.

To me, it's still not resolved. I only get Atmos or stereo on a 1st gen 4k.

So the b update did help but I notice things still revert to stereo.

if I force change format for a second to 5.1 then go and turn it off it will stay in 5.1 for a while.

But it seems it will revert to stereo at some point. Before 18, it would get stuck in stereo sometimes especially after watching something that was in stereo. I found restarting my tv, not the Apple TV, would solve it.

I have Apple TV 4K 1st Gen and use it in combination an older Sony Receiver STR-DB790 and an HDMI audio splitter as the STR-DB790 does not have HDMI. In this way I can use 5.1 surround and also DTS (no Atmos though as my receiver simply is too old). I had no problems at all whilst on TvOS 17.x After updating to TvOS 18.0 I immediately lost all surround (incl. DTS) to the Apple TV box.

All audio was reverted back to 2.0. Strangely enough only the Youtube App on the Apple TV box still gave me 5.1 and 5.1 DTS.

Alle other apps on the Box only gave 2.0. TvOS 18.0.1 did not solve it.

Yesterday I updated to 18.1 (public) and now I have 5.1 and DTS back. I am so happy. So this updated fixed it for me but I read in this thread that others who already had the issue before TvOS 18.0 still seem to have it.

I’ve noticed with 18.1 it seems to work sometimes it only with certain apps. Just now, things in Apple+ and Disney were 5.1 but Prime and Peacock were not. I had to force Change Format to get it (though and I can turn it off and it “sticks”).

I called Apple and they said they had no tickets about the issue according to the Senior Engineer I spoke to. He also believes it’s related to Sonos (which I have), though I told him this thread disputes that.

either way he told me to bring it up with Sonos so that when they said it’s an Apple issue, I could come back and force a ticket by saying I went through Sonos already and Sonos would file a ticket with Apple.

My situation is with two 1st gen 4K units that were putting out 5.1 using change format just fine until the 18 update. The first 18.1 b I download did not fix the issue but another 18.1 version did so I froze them both at this update to keep it working. No other issues have arisen. So I won't be updating to 18.2 if they have broken it again.

Glad Apple has known about this issue since older os’s and have not mentioned or addressed it. Had to get another streaming device so I could have proper sound

i already went to a cheap option. Bought the Walmart brand onn 4k box. Haven’t had an issue since the switch. Puts out the Dolby vision/ atmos

Just update to 18.1 public.

same problem with half solution : disable auto, change format to 5.1, then switch back to auto.

have to do it for each app, so not a real solution

But if it doesn't work with the released 18.1, why did 18.1 b*** fix it?? (It did for me)

Mine stopped switching yesterday. It only output 2 ch PCM. Doesn’t matter whether the ATV 4k is attached directly to the TV with eARC or attached to my receiver. Other devices work just fine. TV is sending full digital signal back to the receiver.

Only Apple TV is stuck in stereo.