Im pretty sure this is a channels issue as i cannot replicate this with any other app.
Setup
Appletv HDMI 1 -> Sony bravia -> earc hdmi 3 to Marantx nr1710
Channels uses default audio driver.
With channels:
audio mode switching works great, 5.1 OTA or imported movies, stereo TVE etc. Marantz will switch modes and then marantx remembers my post processing profile (dolby surround etc). Switching back and forth between stereo and 5.1 content is rock solid. So much so that simulated surround sounds the same as 5.1 to me.
My problem:
If I play ANYTHING that contains atmos audio (atmos plays fine) and then switch to stereo or 5.1 content, my marantz gets stuck in atmos mode for anything i play in channels.
No matter what the source content it will play atmos. Then when i pause the video on Channels i hear a audio mode change click and it goes back to pcm
Then i hit play and the marantz switches back to atmos.
My Troubleshooting:
Thinking this was a marantz/apple issue i tried similar tests with netflix with a mix of stereo, 5.1, and atmos content. Everything worked perfect. No audio issues whatsoever.
I also connected my appletv direct to my receiver with the same results so i know it isnt an earc issue.
Also while channels has the receiver stuck in atmos i can open netflix and the audio mode switching works perfect. Back to channels and problem is there.
My Workaround:
If I NEVER play atmos content, Channels works great. The only thing that i can do is reboot the appletv and then Channels works great... until i play anything atmos. Then i have to reboot again.
After a reboot
Everything is great
@tmm1 @eric i submitted diags from appletv just now after i played atmos content and then switched to a tve recording where it stuck in atmos mode.