No clue. You might have selected a TV code that is not completely compatible with your TV. Try this:
If your TV requires you to use the arrows to select inputs then the Comcast X1 remotes are not going to work changing inputs on your TV. The Comcast remotes only change inputs on TVs that can "cycle" the inputs every time you press the input button.
When I press the input button on the XR5 remote I see the options to change the input but when I press the arrow buttons nothing happens. If I hit input again it takes the box off. What am I suppose to be pushing after I select the input button to change inputs on my tv?