No Character Voice Audio in Xbox -Update: Temp Solution

I have A Way Out on Xbox. When I start the game, I can't hear the voices in the dialogue. During the opening cutscene, I can see the subtitles, but there is no audio for the voices. 

I have tried this in online co-op and local co-op. I have also tried it using a headset and with the TV audio. In all cases, there is no audio for the voices.

All the other audio works in the game from the music, the helicopter, and the bus in the opening scenes.

Can anyone please help?

Edit: Further details. So, I have tested this with two headsets. If I have a headset plugged in, the in-game voice dialogue doesn't play either on the headset or on my TV. So, for example, if I have a headset plugged in, and I take the headset off my head and just listen with the TV, there is no voice dialogue. But if I pull my headset out during the cutscene, suddenly the voices kick in (on my TV). What is going on? As it stands, this game is unplayable for me online with a friend, since - no matter what - the voices don't play if I'm using any kind of a headset.

Edit 2: Okay, so I discovered something. I am using a headset that uses Dolby Atmos. (Specifically I am using the Plantronics RIG 800LX.) I went into the Xbox settings, then went to Display and Sound. Then Audio Output. I then went to "Headset audio." I then turned it from Dolby Atmos to "Stereo Uncompressed." After I did that, the game worked normally. As far as I can tell, this is the only game that doesn't work with Dolby Atmos, but so far, this solution has worked for me.