Loft works exactly as it should in your model. The error is in your expectations and assumptions. You’ve invested tremendous effort in an extremely tedious approach to creating “section curves” without testing first to see if lofting was ever going to work in this case. It’s not even clear to me what you actually expect here? With all due respect, I don’t think it’s clear to you either.
By the way, I am not a “professional”. Ciao.
P.S. More context. You’ve actually created many threads on this topic:
