As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND LOUD WHISTLING NOISE COMING FROM MAIN CABIN DOOR IN FLIGHT. INSPECTED CABIN DOOR AND FOUND PRESSURE SEAL TO BE INTACT AND IN PROPER POSITION. REMOVED AND REPLACED LOWER DOOR SEAL REST IAW SRM 51-40-02. OPS CHECK GOOD, P/N 7253741-257.