As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUELER REPORTED POSSIBLE UNWANTED FUEL TRANSFER DURING FUELING AT GATE. WITH ALL DEFUELING VALVES CLOSED AND AIRCRAFT MANIFOLD PRESSURIZED FROM GROUND FUELING HYDRANT CENTER TANK TAKES ON APPROX "00.2" POUNDS OF FUEL IN A 5 MIN TIME SPAN. REPLACED LEFT CENTER FILL VALVE CONTROLLER, NO HELP. AFTER TANK ENTRY FOUND LEFT CENTER TANK FILL VALVE STUCK OPEN (TANK SIDE). REPLACED FAULTY CTR LEFT FILL VALVE PER AMM, OP CHECKED GOOD.