Sim Objects running away

Hi everyone,

I must be missing something very basic but I can’t figure this out! Why is it that when I place a sim object such as Air Stairs, they immediately start driving straight across the airport?

The same thing happens when I attach them to a parking position also. And it happens for all of the ground vehicles that I place.

What am I missing?!
Thanks

happens to me too!. I just add them as scenery objects instead, they are static that way

cant reproduce that. Have many simobjects at my current project and none of them is moving. Not sure how it would even be possible if there is no animation in the xml.