Xbox streaming audio settings


I have an Xbox One X, Sony STR-DN1080 and Klipsch 5.1 speakers hooked up with a Vizio P series TV. All devices are connected to the receiver and the receiver to the TV.

I have tried all the settings and no matter what, the sound is only coming out of the two left/right tower speakers when streaming. The media is DTS TrueHD or at least Dolby 5.1. What do I need to do to get true 5.1 audio and sound coming from all 5 speakers?