Cancel latching hall effect sensor effect
The document @SteveG linked describes the latching hall effect sensor as latching one value when it detects either a positive ("north") or negative ("south") field and switching to the other value only when it detects the opposite field. Your magnet has both north and south ends, so you should arrange for the magnet to pass north and south across the sensor in one direction when the door is closing and in the opposite direction when the door is opening. If the setup is N then S when the door is closing, and S then N when it is opening, then the sensor will output the latched S value when the door is closed and the latched N value when it is open. The magnet would have to be one where the N and S ends were separated by some distance, like a bar magnet. A disk magnet probably wouldn't work because it would be difficult to pass the N and S sides across the sensor in the manner described.