As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN DOOR: NOTICED THAT WHEN OPENING THE MAIN CABIN DOOR, THE DOOR DOES NOT FREE-FALL OPEN REGULARLY ESPECIALLY FROM THE OUTSIDE. IT WILL POP THE SEAL BUT STAY IN THE SLIGHTLY AJAR POSITION. FOUND DOOR SUPPORT STRUT TO HAVE A STICKY SUBSTANCE ON IT. CLEANED SUPPORT STRUT OPS CHECKS OF THE DOOR IS GOOD AT THIS TIME ALL WORK DONE IAW CESSNA 680A AMM CHAPTER S2-10-40