Over two months since I opened this... Still have not had any official response from @GraceFromGoogle @ChrisFromGoogle. It's going to be a real PR disaster when Stadia is launched and you get people paying $10/month for premium and not getting what they are paying for because google can't support Dolby.
same with me here, i only get Stereo on my Sony 91 Headphones... It has separat LEDs for Stereo or Multi Channel input ..... On other apps Inputs it works fine, it only wont work with Stadia. I am using a high end lg oled, sony 9.1 Headphones and a Chromecast on wifi.