Hallo Umberto,
I think I now know the reason for the many mistakes of the incorrect routes of tankers, baggage loaders or catering vehicles, driving through other vehicles or taking utterly illogical routes.
I did a little test today.
PMDG 737 NGX,
ORBX LOWI Innsbruck, Gate 2.
After landing, log in to GSX for Gate 2. After i had reached the park position and calling "deboarding", the baggage loaders begin to move to the cargo bay doors. At the same time, the luggage carts start to drive, but make some strange curves.
After the discharge, the luggage carts drive away normally, but the baggage loaders move back and forth, sometimes driving through (!) The plane to the left side and then back to the right side of the plane. Then they move in the direction of starting position, but do not place themselves parallel to each other but L-shaped, with one loader is in collision with the other.
I have attached the corresponding picture.
However, if I do a reset of the couatl engine, everything runs normally and as desired, NO vehicle crosses or drives through the aircraft.
I made this attempt several times. Each reset the couatl engine and then either "boarding" or "deboarding". It works flawlessly every time.
However, I have also noticed that in most cases where I arrive by plane at a new airport, the baggage loaders often play crazy.
From this I conclude that GSX has an initialization problem in this case. As it seems, an aircraft, when it comes from the taxiway and then reaches the parking position, is not recognized properly by all functions.
That would also explain the strange driveways "through" the plane, because the plane is not properly recognized and so for the baggage loader the way through the plane is "normal".
Only after the reset is the "normal" initial position initialized and everything runs smoothly.
And, it has NOTHING to do with the AFCAD, since it is only and exclusively the basic positions of GSX at the gate.
Maybe this hint will help you to solve the current problems.
