Page's order isn't working under Page Attributes

Hi,

I have 5 pages under a parent page.
I want to have them lined downwards in my order in my “sidebar” but they don’t follow by my numeric order.

It’s just that they are stuck to the order that were initially created.
The first page that I created has been pushed to the last (lowest) page where I want it to go the upper most location.

Out of my 5 pages, the lastly created page is now seated at the top even though I gave it an order of number “5” under Page Attributes later on.

*The pages were automatically created horizontally on top in the order though.

What should I do? What did I do wrong here?