As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: 1 HOUR +20 MINUTES INTO FLIGHT-GREEN "FUEL OT XFRD" ECAM-CHECKED FUEL OUTER TANK AT 0-LEFT TANK ABOUT 2000# RIGHT TANK 8000# RIGHT TANK QUANTITY WAS FLASHING. AIRCRAFT DIVERTED TO STL DUE TO A FUEL IMBALANCE WHERE IT LANDED WITHOUT FURTHER INCIDENT. NOTE: NO EMERGENCY WAS DECLARED. REPLACED LEFT MAIN HIGH LEVEL SENSOR 17 QJ1 PER AMM 28-46-15.