As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON LANDING THE MAIN CABIN DOOR WAS EXTREMELY DIFFICULT TO OPEN. // SIGN OFF // FOUND THE ACCOUSTIC DOOR SEAL VALVE TO BE STICKING. CLEANED ACCOUSTIC DOOR SEAL VALVE. PERFORMED SEVERAL SUCCESSFUL OPS CHECKS OF THE MAIN CABIN DOOR. ALL WORK PERFORMED REF. CE-560XLS AMM 52-10-00.