Installed new Leviton GFCI unit but doesn’t have power and will not reset- Replaced old GFCi unit and placed wires in exact position as old unit, when power came back on led lit up green automatically but it didn’t have power and couldn’t be reset saw the advice to swap wires top to bottom and vise versa as Leviton GFCIs are normally reserved. Turned power back on and pushed reset, light quickly flashed red then green then off and there is still no power. Any advice on what to do/try next?