As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR DISAGREE ON RETRACTION AFTER TAKEOFF. QRH RESOLVED THE WARNING. ALL INDICATIONS NORMAL ON LANDING. (FLT#3552) CLOSED PERFORMED SERVICING OF THE NLG STRUT IAW AMM. OPS TEST OF THE GEAR EXTENSION AND RETRACTION WAS GOOD IAW AMM. NO DEFECT NOTED OR ANY MESSAGES SHOWN DURING ENTIRE OPS TEST.