As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEFECT 65099: - - INFLIGHT A SUPERNUMERARY O2 MASK WAS FOUND TO BE LEAKING OXYGEN FOR APPROXIMATELY 10 MINUTES. 400 LBS OF O2 REMAIN ( SUPERNUMERARY OXYGEN MASKS ). - - RESOLUTION: DISPLACED L/H FORWARD FACING SUPERNUMERARY O2 MASK PER AMM 35-22-31 R/R O2 MASK STOWAGE CUP PER AMM'S STANDARD INDUSTRY PRACTICES. RETURNED MASK TO STOWED POSITION THIS CLEARS MEL 35-5-2-D MDDR# 121565 MC NOTIFIED.