Last night I was playing Destiny 2 on my XB1X and was hearing discrete overhead effects even though the Xbox was outputting in 5.1 uncompressed. The screen on my receiver (Denon x1400H) said Multi Ch In, which is what it says when receiving a PCM signal. The game patch notes don't mention any kind of spatial or Atmos support, and apparently the Xbox system update yesterday wasn't the one that adds Atmos upmixing. And yet, the sound of birds chirping coming directly from my ceiling, clear as day, via uncompressed PCM. What's going on?