Surface.PointAtParameter Issues with Points location

Good afternoon Ladies and Gentlemen.
I have a problem with a node “Surface.PointAtParameter”. This Node starts to put pointes in not an expected way since my surface start to take quite a curved shape.
Could you give me some advises about what is wrong from my side?

Additional description:
I created a surface from 2 nodes “PolyCurve.ByPoints” using “Surface.ByLoft”. As you can see on pictures with a flat surface the Node “Surface.PointAtParameter” working well but and not well with curved option of the same surface. I think that it is so because Dynamo starts to break surface in a smaller parts but I don’t know how to make the node “Surface.PointAtParameter” to work with the entire surface not only with one section of it.

@m.shcheblykin Try this.

YEA
It is working now! Thanks a lot!
But what the possible reason was in my issue ??? I’m not vary big fan of a Nurbs objects. They have such a weird math definition so they behave while you have big Bends unpredictably (in case of usage Point at parameter Node).

Can’t test this as I’m out of the office, shocking I know. But from what I can see it looks like the shape changed in the recreation.

In the first post the wave of curve 1 was + then - on the Y axis, and line two was - +. In the second post the curves were both + -.

Does the node work if you invert the second curve using @Kulkul’s method?

yes

No idea then… I’ll play with it later if I can find time.