This has been explained in several other threads, and of course it has been done intentionally, to prevent the new (large) fuel truck to clash into the other vehicles.
Depending on which side you place the refueling point, left-side or right-side vehicles will be recalled when refueling. So, in your case, if you want to have the stairs attached, simply reverse the X coordinate of the refueling point to have it on the right wing, so the loaders will be recalled to make space for the fuel truck, rather than the stairs.