Waypoints reverses from Departure Airport

Thank you for your continued support, appreciated.
Airport YMTG Australia
Departure Runway 18
Arrival Runway 36
Aircraft Cessna 152 (About my limitation at my age)
I am ‘Guessing’ but it seems MSFS automatically selects the shortest departure leg (D) reversing the flight plan. This MAY be because I am using the same Airport for Departure and Arrival.
Again, my sincere thanks.
YMTG