Problem about anchored position calculation.

Here is the thing:

In the situation that the anchors are separated with value (0, 0) (0.5, 0.5), the anchored position of the red rectangle should be the vector(the yellow arrow) from the center of the anchor rect, which is (-125, -125), to the pivot position(100, -50), the result should be (225, 75), and so it is.

But if I move the pivot to the bottom (100, -100), I think the anchored position should be (225, 25), but in fact, it is (225, 150)(the green arrow). Do I misunderstand anything or is there anything else that should be considered when the pivot is not at the center?

Are you sure that you moved the pivot to the bottom and not to the top? Keep in mind that the coordinate system of the UI has its origin in the lower left corner.
A pivot on the bottom would have the y-value of 0.

5991788--644498--Screen Shot 2020-06-17 at 10.35.18 PM.png

The problem is that I don’t think the y value should be 150 neither the pivot is moved to the bottom nor to the top.