Likely was originally wired as a single family, with coax running all over the place.... so to make the TV work in the living room and the bedroom on the first floor, it's using the same wire that goes to the upstairs bedroom and living room... there's only 1 coax, so only 1 provider can use it.... gotta stop hooking to the existing in-house wiring and just run things directly from the drop to the box in each location. both installers will assume that the in-house wiring is theirs to use, since it's a single family residence.....
