Using an ATEM with a TV wall processor

I am running the program feed of the ATEM mini extreme over an HDMI cable to a TV wall processor only about 10 feet and for some reason I appear to be getting a black flickering signal. My first thought was that it was a loose connection, however I have tried various HDMI cables that I knew had worked and have also plugged a different media player into the TV wall processor to see if that could have been the issue. I have not been able to identify why the ATEM's signal is flickering when it goes through this processor. The program feed looks great going through our in house projectors and Boxcast, it is only when I attempt to use this TV processor that I am running into this issue.

Any help would be appreciated.
Thank you!

Most TV's have multiple inputs. You need to select the right source.