As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNWANTED FUEL TRANSFER FROM CENTER TANK TO RIGHT MAIN TANK. *S/D* AFTER EXTENSIVE TROUBLESHOOTING AND REPLACEMENT OF LEFT REFILL VALVE CONTROLLER DIDN'T SOLVE PROBLEM. REPLACED LEFT MAIN AFT PUMP DISCHARGE CK VALVE PER MM 28-22-08. OPS CHECK GOOD.