Ok so I went to try somthing here. I went to Dolby website and downloaded an official dolby atmos video trailer. So I downloaded the file and went to play it with wired headphones and tried wireless as well. It says "cant play audio. Audio codec not supported". I have the atmos button blue in settings as well I hope the devs see this and fix this feature
Dolby atmos affects the sound your phone produces, you should notice a difference using any audio turning the feature on/off. The video player your using just can't handle the audio codec version the file uses. Download vlc or mx player and try playing the file again.