I am sorry I cannot remember if I previously reported this another board or not.
Issues relating to moving a stack and undoing the move:
* #1 *
(1) A stack which is entrenched in a structure and then dragged to another region will lose its entrenchment icon at the top of the map sprite.
(2) If you drag the stack back to the structure to cancel the orders, the entrenchment icon does not reappear. However, the game does have the stack in the correct state and the entrenchment icon appears at the end of the next turn.
* #2 *
Generally hitting the delete key multiple times is the equivalent of dragging a stack back to the point of origin to cancel the orders. However, in the case where the stack was originally within a structure, then hitting delete multiple times is not equivalent to dragging the stack back to the point of origin. Hitting delete will leave the stack outside the structure and lose the entrenchment status.