When Apple can fix this audio bug in Apple TV 4k?

I have this setup at home. Apple TV 4k connect to my LG OLED C9 (HDMI 1). Then from the TV eARC HDMI (HDMI 2) connect to the Sonos Arc. LG OLED C9 support ATMOS. Through LG TV apps such as Plex or Netflix, whether audio output is ATMOS (EAC3) or DD (AC3), the audio can be correctly bitstream from the TV to the Sonos Arc with no issue. Only lossless TrueHD is not supported here.

On the other hand, this doesn’t seems to work on the Apple TV 4k. With default Setting -> Audio and Video -> Audio Format -> Change Format to Off, only material with ATMOS audio format can be played correctly on the Sonos Arc. Other format such as DD, only Stereo PCM is playback. In order for Sonos Arc to playback DD, the only way here is to set Change Format to On with New Format to DD. Once this is set, all material whether its ATMOS or DD will be converted by Apple TV 4k to DD format and bitstream correctly to the Sonos Arc. This sound a bit downgrading here since ATMOS will be re-encoded as DD format, at least I get surround output on my Sonos Arc. It’s frustrating but I can live with that.

Obviously this is a software bug since Apple TV 4k can indeed bitstream audio out in ATMOS or DD format, depending on whether the Change Format is set to Off (default) or On here. It’s a shame actually why native LG WebOS apps can output the format correctly without any messy setting but on Apple TV 4k hardware, one has to go through all the hassle to play either ATMOS or DD only (not both seamlessly).

I do hope in the future TvOS update, Apple can have a solution for this. Of course, some might ask why I have to use Apple TV 4k here when I have no issue with native LG WebOS. Haha… answer is simple. I want immersive surround sound on my Airpods Pro :-) Like I said, if the issue I mentioned above is fixed, my setup will be complete!