I don't know if this would cause it, but you may have put the hotspot walk-to point outside of a walkable area, so either your character never finishes moving or he moves out of a walkable area and then is unable to get back when control is returned to the player. Put the walk-to point in the middle of a walkable area instead or make the walkable area bigger so that the walk-to point is completely INSIDE it and see if that helps.
~Wolfgang
~Wolfgang