This was on an older house that had some of the electrical re-done. New panels that were all romex but half the receptacles in the house had no grounds. On this exterior GFCI, the tester showed it had a ground. But when I pushed the button on the tester to trip it, the lights switched to Hot/Neutral Reverse and would not trip. When I pushed the test button on the GFCI it tripped fine. Does that mean it has a false ground? Thanks.