As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUEL SELECTION WAS MOVED FROM LEFT ENGINE TO CROSS-FEED. AFTER FLIGHT, THE FUEL SELECTOR WAS MOVED FROM CROSS-FEED BACK TO LEFT ENGINE. FUEL SELECTION WOULD NOT MOVE. IT WAS DISCOVERED THE FUEL SHUT-OFF VALVE HAD FAILED INTERNALLY AND WAS STUCK IN THIS POSITION. VALVE REPLACED.