Coreldraw x8 home and student Outline scaling

Hi Forum members,

I have a concern which is. When I create for e.g; a square whatever the size. And I make it 2pt in thickness. I then convert outline to object via the menu. Then here is the problem when i resize the shape it does not keep the 2pt thickness? Why not? And what can i do to keep the converted 2pt shape the same thickness no matter what size.