So I have gotten the bug where passengers won’t board my planes or even pass security after checking in at check in desk. Passengers will get off the planes but won’t get on them. They just crowd up in my check in area. My Passenger Service Agents (The people that service the check in and flight desk… I think) will go to the Flight desk and stand there for two seconds and leave and the planes will say that the boarding is complete with 0/189 passengers on board. It is really game breaking because I am losing lots of money due to people just sitting in the check in area and not in the secure part of the terminal. I have all the zones set up correctly I think because I have secure zones and international zones in the right places. I week ago people were boarding and onboarding international flights like it was nothing but now they are just chilling in the check in area.
Safe your airport as the current stage and make a second safe to test with.
Then go in to the test safe close the Airport cancel all flights (closing all stands works best).
Wait till your airport is empty of planes and as many people as possible.
Then safe under an alternate name (dont override the original safe)
restart the game open the alternate safe and open the airport.
Maybe that helps (But please safe the original airport so nothing gets lost if it dosnt works)