Sub-D tangency not reflected after nurbs conversion

Hi all.
With a simple 5 faces Sub-D subd.3dm (92.1 KB)
Zebra analysis shows good continuity:
2020-10-04 18_52_06-Window
But the slider to set Sub-D meshing is not used, so there is no control for better zebra quality.

Converting the Sub-D to mesh gives lets you properly use the slider and the result is a nice high quality mesh:
2020-10-04 18_52_42-Window

Converting the Sub-D into Nurbs gives this instead: (see near the center of the object)
2020-10-04 18_56_48-Window
2020-10-04 18_57_19-Window
G2 is even worse.

So it seems that from Sub-D to Nurbs tangency continuity is lost…?
I am doing something wrong?

Creating more cases is simple and seeing it on screen it seems a… defect on the shape.
I went back in thinking i miscliked something, instead it was just the conversion…

Thank you for your reports @maje90. We are tracking closely related issues for the Zebra Adjust mesh on SubDs, and for the surface quality of SubD to Nurbs at extraordinary vertices.

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