You’re going from a closed curve (that seems to touch at the intersection which isn’t ideal) to two open curves and grasshopper isn’t quite sure what you’re trying to achieve with the loft. Even just looking at it - how are you imagining the loft to look? Why not spit the single closed curve into two closed curves instead so they can branch off when encountering the curves in the middle?
Thanks for the input! @ftzuk, the curves touch at the intersection because it is the ideal toolpath to 3D print a certain material.
As @11165 and @inno also suggested, it has to be lofted in 2 curves, or manually SubDed
I’m still curious to know if someone might find a way to do this through grasshopper, because this is a simplified version of a much larger and complex set of curves. It would save enormous amounts of time