First thing to do is check all external and internal coax connections. It's quite possible the internal ones are loose, and external ones are corroded. Take corrective steps if required. The Batwing is directional so raise the antenna and turn it towards the nearest channels(s) and do a channel scan.
I've had a booster on every Winegard antenna I've ever owned so look for another coax connection. May be in a cabinet, in the bedroom. Mine is on the wall, near the floor, by the passenger seat. They can put them anywhere.