You're on top of the "inside FC house" zone. Since the outside of the house is a separate zone, there's no need to model the outside while you're inside it. The other part to this glitch is that sometimes, when going in and out of the Duty Finder, your y-coordinate is not saved properly. Particularly if you were standing on top of a desk/table upon going into a duty, I've found that the game will sometimes place you above where you left when you're returning to where you came from.