Apple TV 4K HDMI to Onkyo TX-NR6050 Not Working

My Apple TV 4K connects via HDMI to a Sony A80CJ TV and the audio is output via HDMI eARC to an Onkyo TX-NR6050 receiver and 7.1 surround speakers. However, when I try to connect the Apple TV to the Onkyo via HDMI, I get at best a blue screen at worst the TV says there is no input. I have tried changing the HDMI input settings on the Onkyo to "4K Enhanced" as well as "4K Standard" and "8K standard" and "8K enhanced". Other inputs including a Roku and BD-DVD player work well connected via HDMI through the Onkyo.

Has anyone successfully the Onkyo TX-NR6050 with the Apple TV? Is there a hidden setting that I have missed? Thanks for any suggestions.