Dragging the selected region works only for the last selected cell, not for all your selection. If you put 1 2 3 , select them all together and drag it becomes

Dragging the selected region works only for the last selected cell, not for all your selection. If you put 1 2 3 , select them all together and drag it becomes 1 1 1 1 1 not 1 2 3 4 5