(Geonodes)Problem with setting position of certain primitives[Solved]

Support Modeling
1

I want to place a filled Quadrilateral curve (basically, equivalent to Plane) in the center of a particular face. Here is how setup looks with the object at the coordinate center:

The cube marks the position I need it at. But then I actually set the position of a plane (Set Position node in Offset mode), it is completely off

The position coordinates itself are correct, since if I use most other primitives (such as cube), they appear where I want them. Only Quadrilateral spline and Grid (with some particular settings) give this error. What is so special about them?

2

Here is what happens with Grid primitive. 3x3 (or more) grid functions correctly, while 2x2 is off place

3

With more tests, I understand even less. Tried to delete select faces of a Cube with Separate Geometry, and it seems that the coordinate center of this new mesh recalculates relative to its bounds

4

Was my error in accessing attributes.