Parametric superstructure family is twisted at long curvature point

Could you help explain why, after a certain distance near the curve, the superstructure Revit family that was created, and imported into a Revit file, and loaded on the defined axis gets twisted as shown in the figure? Not just the family I defined, but all predefined families are experiencing it as well. I don’t know why this is taking place. I hope you can relate to me and let me know how to resolve this.

I recommend to split the superstructure. Also use the command
“Check self-intersecting geometry - additional check and correction (division) of created solids in the component family will be performed. Relavent in case of significant curvature of axis.”
to avoid this problem.

See also our manual