Hello,
I've been refueling lately the A320 (FSLabs) and the 737 (PMDG), and it seems that the truck is too big for them. Does the developers intend to create a smaller truck?
Also, the rose attachment point in the 737 is wrong, it's much closer to the engine in reality.
Now, as to the A320, the truck goes "below" the airplane right in the longitudinal axis line and gets stuck in there, it won't go away so it's impossible to start pushback thereafter.