According to the PacHy Service manual, that is indeed a "Fuel Door Stuck Open" DTC.
The switch function which determines status appears to be in the lock-unlock solenoid assembly. It just says to see if there's anything in the way or broken in the door lock mechanism and thereafter, it's a bunch of detailed checks of the electrical system. If you can pull the door open from the closed position with your fingernails (or trim tool) or it's not flush with body panel when closed, that is likely a mechanical problem. Looks like a trip to the dealer is in order.
I haven't seen that DTC on my 2017 PacHy. (Knocking on wood....)
2017 Silver Teal Hybrid
2014 BMW i3 REX
2005 Grand Caravan SXT
2003 BMW 530i
2000 BMW 528iT