I've had TWO brand NEW 5th wheels that had TV reception problems. 2001 Laredo had a bad coax between antenna and TV amp. Not discovered until I had new roof installed (10 years later). I always thought we just had bad reception in the SP we camped at, plus we watched little TV camping. Mostly DVDs.
2015 Glacier Peak had issue OP is having. TV reception fair in living room nothing in bedroom. Dealer ended up replacing the amp and we now have excellent reception on both TVs. Don't know if they also replaced any wiring.
Safe Travels!
Mike
