Concave tensile surfaces

Hey everyone! I’m new in Kangaroo and I’m trying to get a concave tensile surface. I have problems when I move the control points to the concave area. The tensile surface makes an irregular movement and does not allow me to achieve the shape I want. Is there a way to work with a concave irregular mesh. I undesrtand why, but no idea how to solve it
Any idea? Thanks
Attached some images to be clearer
The problem

The shape i need

Grasshopper definition

Hi Martin,

I can’t understand the issue you are having from those images and description.
Maybe post the rhino file?

Hey Daniel! Thank you!
I updated the shape but is the same issue. I also copy the “final form” i did in rhino, but now i need to apply the Kangaroo physics and I really dont know very well how to do it. I appreciate any help.
Hope tath’s enough for you to get my issue.
Thanks again.

Kangaroo.3dm (519.9 KB)