What is the working direction of powertrain subsystem?

Hello, I modified powertrain and driveline templates from acar_concept folder ​for the needs in my vehicle model. However, they only work properly in opposite rotation direction. In Acar powertrain model setting, there is nothing about its rotation direction. However, in a vehicle model, the powertrain only work properly in one rotation direction. This problem can be repeated in a demo model "sedan_RWD" in acar_concept folder. First run this vehicle model on the default flat surface for an acceleration straight event. Then check the box "Invert output direction from input direction" in its differential gear model. This forces the driveline rotating in opposite direction and so the powertrain rotation direction. Run the same acceleration event. The vehicle performs completely different in these two scenarios. My question is what generate the differences. Thanks in advance for answering my question.