Tracking down television cable connection?

[432bartman]

So after a 4 hour drive to our destination, hooked up the rig to the site's television cable, and all three televisions we have our not clear and have a "snowy" effect. I hooked one TV directly up to the site's cable and the TV is crystal clear, so that eliminated it being a problem with our RV site or the TV itself. I then unscrewed the cable/sat connection panel that's on the driver's side where the water connection is, and found all the cables somewhat loose. Tightened those and still the same problem. I checked all the cable connections where the main TV is located and all our tight. My question is, where do I look now? Our rig is a 2019 3560RL with the motorized television in the desk. From where the cable comes into where the main TV is, it disappears into the floor. Is there another connection I can reach behind the storage bay two side panels where say the water pump is? Truly frustrating.