As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURN FROM FLIGHT, A HISSING SOUND WAS HEARD JUST AFTER VR COMING FROM THE L-1 CABIN DOOR AREA. THE AIRCRAFT FAILED TO PRESSURIZE, CAPTAIN DECIDED TO RETURN TO MYR. AFTER LANDING MAINTENANCE INSPECTED THE DOOR AND FOUND EVERYTHING TO BE NORMAL, NO DISCREPANCIES FOUND.