As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY OXY PANEL 12 DEF FAILED TO OPEN DURING OPERATIONS TEST. INSPECTED AREA & FOUND HOSE TO BE WEDGED. REPACKED THE MASKS & PERFORMED OPERATIONAL CHECK OF MANUAL RELEASE. THE EMER OXYGEN PANEL AT SEAT ROW 12 DEF OPENED AS REQUIRED.