As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING DESCENT CABIN PRESSURE WAS LEADING PRESSURE DIFFERENTIAL MORE RAPIDLY AND GREATER THAN NORMAL. DETERMINED THAT THE OUTFLOW VALVE CONTROLLER WAS NOT CONTROLLING OUTFLOW VALVE MOVEMENT PROPERLY. NO OVERPRESSURES (DIFFERENTIAL) WERE NOTED. PART WAS REPLACED WITH SERVICEABLE CONTROLLER AND ALL SYSTEM FUNCTIONS RETURNED TO NORMAL.