Loft problem

Start a new thread. Look more closely at your geometry. What appears at first glance to be four curves is actually 12 curves with short fragments duplicating longer curves. What you are doing after that is a mystery to me, though I can see that the ‘Curve’ input to Sort Along Curve is not internalized. Code, geometry and data trees should make sense every step of the way.

It appears you are doing something like this?