We have a Marantz 8805 in our family room zone connected to a Sony OLED. I had two HDMI outputs running from the Marantz to the TV. One Arc and another normal. I really ended up not using the second, but it was still connected. Most of the time when playing a 4K Dolby Atmos movie, I could not get the Marantz to accept the audio signal being Dolby Atmos. 4K video was fine, just the audio was not correct. Finally I turned off the dual video output from the Marantz to only one video output. Dolby Atmos now works fine all the time from the Strato. What was strange was that other 4K Dolby Atmos worked fine from sources like ATV, but just not the Strato. Maybe because of the Strato begin full DD va. DD+ or something. Anyway, just FYI if there are other Marantz users out there that are using the dual output. Likely HDMI EDID craziness! SJ