940C and Apple TV 4K
Something interesting, after finally deciding on the desired ATV output settings I enabled Standard for HDMI output on the TV, even though it was already set to Enhanced. Then enabled Enhanced again, The picture really came to life. Possibly the TV wasn't locked in correctly after trying out so many different output resolutions from the ATV during the last few weeks.
Just figured there might be someone out there who would want to try this as well since most of us ATV 4K owners have been forced to play with its output settings due to the lack of a native resolution option.