So normally when you hold the space key and drag, it just moves the canvas, but every now and then, seemingly randomly, it zooms way out and shows a little box which is the size and shape of the area of canvas I was previously looking at. If I move the box and let go of space, it zooms to that location, but all I wanted was to move normally. I don't think I've ever wanted the zoom out, move, then zoom back in behavior. What causes that? How do I make it stop?