In the past, with the exception of our TA in April 2022, immigration came on ship prior to arriving at debarkation port to clear passengers. Boarded at some point at one of our ports in Europe.
This past April on the Odyssey of the Seas, missed our first port in Europe. Never cleared passport control and left ship after B2b in Rome. No immigration check. Flew Rome to USA via Frankfort where had to go thru passport control. Had to prove to agent how we arrived in Europe. Had no record of our arrival.