Area moments component validation issue?

A Grasshopper validation issue: Z component shows Ix instead of X component
According to my memory and the textbook, we need to calculate the Second Moment of Area (Ix) for bending when the load is applied along the Y axis, as shown in this graph.

I attempted to validate the grasshopper using a simple rectangle with dimensions of 10mm(width) by 20mm(height). However, I was confused by the results, as the Z component seemed to be the relevant one, instead of the X component as I expected.

It seems that Z component get Ix, X component get Iz for second moment of area.

And if validate those in other planes, same thing exists.

Can I know if this is a bug? It seems not right on its axis?

Version: Rhino 7+ Grasshopper Version Monday, 17 April 2023 03:00 Build 1.0.0007

Q_contour_across Y (8.8 KB)
Second moment of area calculation.3dm (2.9 MB)