If the button doesn't work for you try this. The marble top can be removed by using a small knife of screwdriver, it just sits on the tv raising mechanism with two long posts. Remove that and check your tv connections. There are four wires, three are audio and one video, and one is coax. My video wire was off but I believe this is only used for piping in your own video. The coax was a little loose, so I screwed it on hand tight and also undid and reinstalled the coax short connector wire. Then I got my stations.
Thise wires are not strain reliefed and need to be. Every time the tv goes up and down the weight of the cables are being pulled. I told Jayco they needed a strain relief and they said they are going to mention to their mfg people. Mine is a 2016 31ul.