As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: LEFT ENGINE DUCT PRESSURE INDICATES 0 ON CLIMB AND CRUISE. FLIGHT ATTENDANT REPORT NO AIRFLOW IN CABIN. FLIGHT AIR INTERRUPTED BACK TO MIA. NO EMERGENCY DECLARED. REMOVED AND REPLACED PRESSURE REGULATING SHUT OFF VALVE (AALA202302015650) IAW AMM 36-11-03,REMOVED AND REPLACED PRE-COOLER VALVE (AALA202302018831) IAW AMM 36-12-02. REMOVED AND REPLACED HIGH PRESSURE REGULATOR (AALA202302012675).