It looks like your 150' curve is a fillet between two elements, and the ahead element terminates at the same spot as your curve, so that when your curve clips the ahead element, it has nothing to clip.
As a solution, can you exclude that last element from your complex profile?
Alternatively, can you extend that ahead element just slightly so that the clip works properly?
As a solution, can you exclude that last element from your complex profile?
Alternatively, can you extend that ahead element just slightly so that the clip works properly?