As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW DESCRIBED HAVING A PRESSURIZATION ISSUE DURING THE CLIMB AFTER TAKEOFF. THE FLIGHT CREW ELECTED TO RETURN BACK TO THE AIRPORT AND LAND FOR MAINTENANCE CONSIDERATIONS. THE BASE MAINTENANCE TEAM INSPECTED THE TAIL AREA AND FOUND THE WATER SEPARATOR SLEEVE TO HAVE SHIFTED OVER CAUSING A LOSS IN AIRFLOW LEADING TO THE PRESSURIZATION DISCREPANCY. THE SLEEVE WAS REPOSITIONED AND SECURED, LEAK CHECKS WERE SATISFACTORY AND THE AIRCRAFT WAS RETURNED TO SERVICE.