The connection of the refueling pipe to the fuel truck in MSFS 2020 is made through a pipe that the new planes have in the 3D model. The service vehicles read the configuration of the aircraft to position themselves exactly where the 3D pipe of the plane ends. The data in the flight_model.cfg file relating to the position of the Fuel hose in the airbus A320 NEO are incorrect and precisely the line:
interactive_point.9 = 0, 0, -54.59, -7.57, 3, 0, 0, -90, 0, 0, 0, 0, 0, 0
is wrong, the correct one is:
interactive_point.9 = 0, -13.11, -54.59, 1.14, 3, 0, 0, -90, 0, 0, 0, 0, 0, 0
This causes the refueling truck to position itself incorrectly as in this screenshot:
I have described the problem to Microsoft, and I hope it will be solved. While waiting for the solution, you can edit the file as I described above, but remember to make a backup before making any changes.