As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AIRCRAFT RETURNED TO BASE AFTER NOT BEING ABLE TO MAINTAIN CABIN PRESSURIZATION ABOVE 23,000 FEET,. DURING GRD PRESSURIZATION CHECK FOUND HEAVY AIR LEAK FROM L/H PRSOV AND C1 CARGO. C1 CARGO FOUND NET OVER CARGO DOOR SEAL, NET REPOSITIONED. PRSOV LOCKED IN THE CLOSED POSITION PER MEL 21-31-00. GROUND PRESSURIZATION TEST ACCOMPLISHED IN ACCORDANCE WITH AMM 21-31-00, AIRCRAFT RELEASED.