Did you run a jumper from the tap to the DVR in the home? Also, run that same jumper to your test unit at your truck. If their DVR is breaking up on that line but your truck unit isn't, then suspect their DVR or power supplying it. Put your test DVR on their outlet and see if the same problem occurs. Also, confirm that it isn't their TV set by running the output of their box over to your test set using the same type of connections.
This is CABL.com posting #226254. Tiny Link: cabl.co/m61q