tvOS 12: No HDMI audio output available

Did you ever find a fix for this? I have the same issue. 6 apple tv’s in the house that all updated when ios12 came out. The one in the home theater with older but high-end receiver and projector setup had no sound. Many phone calls with Apple and they suggested replacing a $4500 receiver which is unacceptable. HDMI out is no longer a source in audio setup. It isn’t this way on any of my other apple tv’s. We seem to be in a very small group of affected users so I’m not optimistic. Fortunately I used a non 4k gen 4 and hooked up to my computer via usbc to downgrade (Apple was no help with this btw). For now just have to keep refusing to update when the option comes up as I will likely be back with no sound until apple comes out with a new update.

I have the same issue using an older A/V receiver. Everything worked fine until the tvOS 12 update. I tried every HDMI port on my receiver and still nothing. I have called Apple on this but no resolution. I also called the A/V receiver manufacturer and they no longer provide firmware updates for the receiver. This is really going to suck if I have to buy a new receiver just to be able to use my Apple TV.

I'm in the same boat. I have 2 Apple TV 4K devices. Both were updated to tvOS 12. The Apple TV for the basement is part of a full surround sound system. The sound is working without issue.

However, the Apple TV for the family room - which has a sound bar - is no longer working. I tried different HDMI ports and swapping the HDMI cable. Nothing worked.

I noticed the audio output settings no longer lists HDMI as an option. It only lists the other Apple TV in the house.

Clearly a fix is needed from Apple. Please post if a workaround can be achieved and/or when Apple releases a fix for the issue. Thank you.

See this thread for additional info - Apple tv sound not working