I create a new file in Illustrator. 30 x 30 px. No stroke just black fill.
I create a new rectangle 27 27 px
I select the rectangle and go to the icon align to artboard
I click to the icon Horizontal Align Center and Vertical Align Center
It moves but it does not align in the center
I do not understand. Is there anything else I have see. I am sure there is not guides, no other objects. I closed and open Illustrator and still does not center.
I have the same problem if I create a new document with any new rectangle. I do not know what else to check.