Passengers are stuck behind closed gate ... bug?

[FastLawyer]

So I'm at the second airport, shift 1. Finished all the shifts in the first airport. So no bags come in the 1st shift of the new airport. Everything is going fine until all the passengers in one line have finished and then the passengers in the other two lines are stuck behind closed gates. Only the passengers that managed to get to the third (furthest away) gate got through.

The game just sits there. Time expires. Nothing happens. Can't finish, can't go back to main menu, there's nothing to do. I looked everywhere for a way to open the 2 locked gates.

Is this a bug?