As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN ALTITUDE WAS HIGHER THAN NORMAL, NOTICED THE CABIN RATE CLIMBING @ 1000' PER MIN. THEN HEARD A WHISTLING NOISE CLOSE TO THE CABIN DOOR. "CABIN PRESS LD" LIGHT CAME ON. ONCE WE REACHED BELOW 20,000' THEN THE NOISE GOT QUIETER AFTER WE SELECTED "BOTH HIGH" ON THE CABIN PRESSURE CONTROL. CABIN WOULD NOT MAINTAIN PRESSURE UNTIL WE WERE LOWER AND IN. "BOTH HIGH."