Several of us on the Grand Design forum were having similar problems with the coax runs for satellite in our rigs. My solution - and implemented by a dozen others with success - was to use a "through-hull" coax port in the floor of the slide where the entertainment center is with new coax from that to the satellite receiver inside. For the newer automatic antennas that use the same coax cable for signal, power and control, it's best to use quad-shielded coax cable for both the inside and outside runs, too. Having bypassed the cheap coax, poor connections, and long runs of the OEM cabling, we now have zero issues with our satellite TV system.
Rob