In my 2016, I found connections loose behind the wall plate, and at the splitter to the bunk room and bedroom TVs. Cable would work on main TV, but broke up on the others.
I also found lots of campgrounds have very low cable signal. (Split too many times). I am going to purchase a single port amp to take with me to amp the signal into the camper if needed. They are only $20 or so.
2003 GMC Serria 2500HD - Lotsa Mods.