I've got a '14 Grey Wolf, and was having a similar issue...
I'm assuming the cable works in the campground, and the issues are on "your" side, since you mentioned it's happened at multiple locations.
Easy way to prove that would be running a long cable from the campground service directly to your TV and ensure that works... That'll isolate the problem into your trailer system.
First off, have you got the TV connected to the "Sat/Cable" jack, instead of the Antenna jack inside?
Second - my Cable inlet was mis-wired from the factory - the cable connection on the side of the trailer was correct, but it wasn't correct at the jack panel above the TV. When I corrected that, my cable and sat experience got drastically better...