Wire Structure Tutorial Problem

Dear all grasshopper fans,

Hope you enjoy "parametrical" week :) About my problem, i'm trying to do a wire structure which is from Rodrigo Ruiz's tutorial. At the first step, i've done the same as expected but the result of the first step is different as you can see in the picture attached : the final shape is "flat". Did i miss something ? Or something has been changed ?

THanks and best regards

El Mehdi