Slumped Triangular Surface Using Network Srf with 4 Base Curves

Hello,

Trying to use Network Srf in GH but experiencing problems.  There are 4 base curves -- 3 defining the boundaries of a triangular shape, and 1 defining a sectional profile.  Firstly, Network Srf in Rhino works perfectly fine for this issue.  Secondly, when the central profile curve is made smaller, it works, but with the wrong results.  Attached are the files for anybody's reference. 

Any advice would be much appreciated.

Best, Hannah