?? What double vehicles ?
You are "normally" supposed to have two loaders and two baggage cart, on in front and the other in the back.
However, if I'm not mistaken, that's an Aerosoft A318/319, and for that particular plane, we configured it to have only the back loader, because they just won't fit, especially if you also call catering (the plane is too small).
So, it looks like you configured it to restore the missing front loader, which now makes clear why we removed it in the first place...the plane is just too small to show two loaders together in many situations.