TV's don't generally "pass through" audio via their digital link. They only send out audio that originates from within the TV.
To do that you'll need to use the red/white analog audio from the TV to the Denon but it'll only be stereo. That, TV's WILLl "pass through".
For MC sound from the Fantek, you'll need to run an audio link directly from the Fantek to the Denon.
With that in mind, recheck your input setup.