I had a similar problem with my outside TV. I pulled the connector from the side of the trailer and found that the connector on the end of the cable had not been stripped and crimped correctly. I restriped the wire and put a better connector on it and now all is well. They use very cheap coax in these trailers and I can see if not doing it with just a little attention to detail how they could work loose.
Retired Fire Dept Battalion Chief
2016 Ever-Lite 232RBS
2012 F150 FX4 W/Max tow & Ecoboost
Getting old ain't for wimps!!!