Dragging an area against the edge of the map shrinks it

When I click and drag an area to the edge of the map in map editor, trying to drag it beyond the edge of the map causes it to shrink. I would expect that the map editor would simply not allow me to move the area outside the boundary but leave it the same size. When I release the mouse button, and the shrinkage leaves the area with a width or length of zero, I can no longer click and drag on the edges of the area to expand it any longer. Clicking and dragging on the square at the top or bottom of the area after selecting it has no effect. It can no longer be dragged away from the map boundary if I leave it there instead of pulling it away before releasing the mouse button.

I have created an area called “Bug Test Area” in my campaign to reproduce the error for testing and dragged it against the far right edge of the map in case you want to take a look.s