As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CLIMBING FROM FLIGHT LEVEL 240 THROUGH FLIGHT LEVEL 260 CABIN PRESSURE OBSERVED TO BE ERRACTIC. SLOW DESCENT INITIATED WITH NO CHANGE. CABIN EXCEEDED 10,000 FEET. RAPID DESCENT CARRIED OUT AND CABIN PRESSURE CONTROLLED AT FLIGHT LEVEL 200 FEET. MAINTENANCE CHANGED BOTH AUTO PRESSURE CONTROLLERS. SYSTEM CHECKED SERVICEABLE.