What Jerry said would work if you had a discrete splitter, but most RVs have the power injector integrated into the splitter, so bypassing that would mean no amplification in the antenna and almost a 0% chance of getting any channels these days..
It is likely you have a poor coax connection somewhere: Check them all for tightness including the ones on the roof if you have the Winegard Batwing antenna.. I did have one travel trailer with symptoms as you described and it turned out the amplifier board in the batwing antenna had gone bad.
Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad
2020 Chevy Colorado Z71 Trail Runner Alternate Toad