Originally Posted by Pacbellguy
Our set up sounds exactly the same. Not sure why I'm having trouble. When I do the Apple TV test for DV, it always reverts back to previous format which is the 4k SDR
I assume you get DV, like you said, when connecting directly to the TV—so most things are working...
A few things to double check:
My TSR-7810 firmware is 1.32
Video mode is direct
4K Mode is Mode 1
My Sony 940E firmware is PKG6.2858.0082NAA
I'm using HDMI 3/ARC; fyi ARC works with the Yamaha (HDMI 2 should also work for HDR)
I'm using Enhanced mode (it won't work without it)
i.e. Settings > External Inputs > HDMI Signal Format > Enhanced
My ATV 4K firmware is 11.3 (kudos to Apple for keeping it current)
Output is 4K SDR; YCbCr; Chroma 4:4:4
Match Content is set to Range & Frame Rate
You could set the output to 4K Dolby Vision for testing. I personally prefer Match Range—that way when DV content is played, I can immediately tell it's working when the Dolby Vision logo (briefly appears). Also for HD content, the TV is doing the upscaling, i.e. not the ATV. That's one of the strong points of the 940E, the upscaling.
Hope this helps. You could always try unplugging all power, using a different certified HDMI cable, etc. Worth figuring out now even if you go for a higher spec receiver.