Problems with HDR/Dolby Vision on Apple TV 4K

Folks,

I have been racking my brain trying to figure out this problem. I have an Apple TV 4K on the latest firmware (13.2 17K82)

TV - Sony XBR75X950G (Supports Dolby Vision)

Cables are Monoprice 18Gbps HDMI (I have about 25 of these cables in use throughout my systems and they work just fine with Dolby Vision)

Connecting the Apple TV directly to my Sony TV, I am able to select all the way up to 4K Dolby Vision 60Hz. I've checked this with 6 different Monoprice HDMI cables

When I introduce an AV receiver I have issues. I have tried 2 different AVRs.

1st AVR Onkyo TX-NR656 (Enabled Enhanced in the menu...can't remember exact setting as I have it disconnected now)

Symptoms:

4K Dolby Vision - Blank Screen

4K HDR Works

2nd AVR Denon AVR-X3500H (Enabled Enhanced in HDMI menu)

Symptoms:

4K Dolby Vision - Half of a green screen

4K HDR - The screen is green (rather than gray)

I have tried swapping cables around.

I also have an LG UP970 UHD Player connected to the AV receivers. Dolby Vision and HDR10 work just fine for it.

In addition, I have another Apple TV 4K connected to a Samsung HW-Q80R and it too is having issues passing Dolby Vision (but it will pass HDR)