As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, THE OXYGEN MASKS IN THE FORWARD CABIN EJECTED. TROUBLESHOT PROBLEM TO BE A PINCHED MUX SYSTEM CABLE AT SEAT ROWS 6ABC AND 7ABC. REPLACED THE MUX CABLE AND RESET ALL OXYGEN MASKS THAT DROPPED. PERFORMED OXYGEN DROP TEST PER MM 35-20-00. PASSENGER OXYGEN SYSTEM OPERATIONALLY TEST NORMAL.