Problems in obtaining the direction of the cross section (different from the visible one).

ProSurfaceXyzdataEval returns a different normal orientation value for the same section in the same direction.

Photo 1. Select the surface that shows the section. Direction is left.
Photo 2. Select the back side of the surface that shows the section.Direction is left.

I attached used code.

status = ProDrawingView2DSectionGet(drawing,view[i],0,xsec.xsec_name,&sec_area_type,&ref_sel,&curve_data,&arrow_display_view);

status = ProXsecPlaneGet(&xsec,&planeGeom);
status = ProSurfaceToGeomitem(DrawingViewSolid, (ProSurface)planeGeom, &surfaceGeomItem);
ProSurfaceDataGet((ProSurface)planeGeom,&geomItemData);
ProGeomitemdataGet(&surfaceGeomItem,&geomItemData);
halfUvParam[0] = geomItemData->data.p_surface_data->uv_min[0] +
(geomItemData->data.p_surface_data->uv_max[0] - geomItemData->data.p_surface_data->uv_min[0]) / 2.0 ;
halfUvParam[1] = geomItemData->data.p_surface_data->uv_min[1] +
(geomItemData->data.p_surface_data->uv_max[1] - geomItemData->data.p_surface_data->uv_min[1]) / 2.0 ;
//ProGeomitemdataFree(&geomItemData);
ProSurfaceXyzdataEval((ProSurface)planeGeom, halfUvParam, point, deriv1, deriv2, s_normal);

Use the above code to get the vector of the section.
Vectors also appear differently in cross sections in the same direction.
The reason is that the surface of the cross-section reference is front or back.

How can you get the direction shown by the red circle on the cross section?
I do not seem to be right in the way I use it.
Please help me.