TV won't register any ports at all. Channel 3 just Fuzz

Ch 3 is only for things plugged into the ANT jack. Any port inputs like HDMI must be selected as an input. That is what the INPUT button on the remote does (sometimes labeled as something else). The fact that they are all checked on your setup only means that they are available as inputs, but you must select one. Hitting the channel button usually reverts the input to ANT. The Roku I have will cause the TV to change to the HDMI input if I hit any button on the Roku remote. Not all do that so you must change the input to the HDMI port the Roku is connected to.