After two years and two inverter repairs, that were rather expensive, we discovered a water leak from a T-Connection on a cold water line. That T was hidden behind a panel under the galley sink in our 2015 Bounder 35 K. We thought the water was coming in from the outside, but during the second repair, we dry camped the night in the parking lot of the repair facility. We had used the sink that night, and the water came down into the bay along an electrical line that came down from the inverter monitor to the inverter. The repair person found the source of the leak. We left the facility on a two week trip. We checked for moisture every day. Once we tightened the connection, we have not had a problem.
Good luck on your search for the source of the water.