Can it get Dolby Atmos?
To get subs in both, swipe up on the remote, Netflix, it should be on the right side and left bottom on Prime.
I have Apple TV to the tv, audio and vid settings are enable Dolby, format-4K SDR, Match Content-both, Audio Format-auto, dolby available and the change format-off and Immersive Audio-dolby Atmos is on.
Just for fun try HDMI connection setting.