If your movie isn't playing back with DTS-HD, please make sure you have DTS-HD audio turned on.
go to Setting -> Audio -> Format, and make sure DTS-HD is checked.
Remember, not all movies have the DTS-HD audio track. Look for the DTS-HD logo within the movie details page on your device. If DTS-HD is turned on but not available on a movie, CinemaNow will playback in AAC 2-channel stereo.
In order to play DTS surround sound, you must have a DTS enabled device (Xbox One, or a DTS enabled TV or Bluray player) a receiver component system that is DTS enabled, and play an HD version of a title that has DTS.
DTS playback using the CinemaNow app is currently available on Xbox One, and most Samsung 2013-2016 Blurays/TVs/Home Theater Systems.