You know, it really is ridiculous how the HDMI spec changes and new features are added but nobody is compelled to include ALL of the features of the new spec and the older specs get left behind. So, as new devices hit the shelves, there is no telling what kind of issues one may have when connecting a new TV to a two year old receiver along with a five or ten year old video device. Full backward compatibility and a full feature set should be mandatory. Oh, and you can’t include those features until the HDMI spec is finalized. Can you imagine the headaches if the wifi standard worked in such a way?
You might try changing the video output of the Directv. Some resolution settings might work better than others. Turn off any upscaling in the Denon. Oh, and check that cable. Post any info. Some use clever ads but aren’t actually Premium Certified.