The "Position" Input does not do what you think it should be doing.
If you open the Wall Settings Dialog in ARCHICAD you will find that this parameter is located in the "Classification and Properties" panel, it is relevant to Energy Analysis, it does not affect the geometry.
If you right-click the middle of the Component (the vertical bank in which the icon is shown, you will find a context menu on which you can select the Reference Line Location, any one of the available 6 options.
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