Restoration company melted a GCFI in garage with a huge dehumidifier. Went to replace it with a new GCFI receptacle. Tested the sets of wires coming in to determine line/hot. When the line end is connected and ground wire connected the tester reads “good” for that outlet (down line GFCI receptacles “no power”) but as soon as I connect the loan end the GFCI trips. The load end is a pigtail. If I remove the new GFCI altogether and connect the hot lines to the pigtails of course all the down line GCFI outlets test “good”. What could be wrong here?