C61 not compatible LG 4K in HDR Mode - DirecTV

C61 not compatible LG 4K in UHD Mode:

I have a C61 / HR54-500 / Integra DSX-3 / OLED65B6P all firmware up to date.

Audio problems persist on the C61 unless I use optical out which is fine with me. My big problem is that when I switch to a 4K channel on the C61 I get no picture unless I switch the LG TV to non- HDR mode. Thereafter, I do see an obvious 4K picture but it's a pain to switch as the LG has to reboot to change that mode. Note that my other devices such as Roku Ultimate 4K do work in HDR/UHD mode and that I have the same issues when bypassing the Integra and going directly into the LG. (just with the C61)

I understand the C61 may not output HDR but it shouldn't fail when attached to an HDR 4K TV. Other non-HDR 4K devices don't have that issue.

I realize my LG has an RVU but I can't use that as it is built into the wall and I do have an HDMI 2/2.2 cable but no coax as it was set up and the wall 'closed' before RVU was out.
I should not be having the C61 compatability issue in this configuration. Anyone have any ideas?

This question, "C61 not compatible LG 4K in HDR Mode," is about DirecTV channels, programming, equipment, and sports.