I recently bought a LG C9 OLED TV. I also have a Marantz receiver connected to the TV via HDMI ARC. In the TV I now have "passthrough" in the sound settings.

With these settings I get stereo via the Youtube app but with the Spotify app I get DD surround sound on my Marantz receiver (up mixed I guess). Of course I want stereo sound as intended on "all" music. I know that I can change settings to "PCM" but then I get stereo from all my apps lika Plex, Netflix and so on but they have surround sound tracks and of course I want the surround sound in those cases. 

Does anyone have the same problem? Any solution? If not I urge Spotify to fix this - if it works with the Youtube app I see no reason for it not to work with your app. If there actually are people who want music in "fake surround" which is not intended with the music I think its their problem and they up mix the sound with their equipment. Or at least I should be able to choose in settings in the app.