As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: FLIGHT DECK DOOR DOES NOT OPEN FOR IN FLIGHT. MAINTENANCE FOUND THE IN-FLOOR VENT PANEL BELOW FLIGHT DECK DOOR HAD AN INCORRECT SCREW INSTALLED THAT WAS INTERFERRING WITH THE OPERATION OF THE FLIGHT DECK DOOR. REPLACED THE SCREW WITH THE PROPER ONE AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK OF THE FLIGHT DECK DOOR PER AMM 20-21-13.