Even though the curve segment lies on the surface within model tolerance, their _Intersect result is a point, but when the curve is part of a polycurve, a full overlap curve is created.

This occurs in 7.25 and 8.0.23003.14305, 2023-01-03.

Hi Steve - I see that, thanks. The pulled version of the curve does intersect fully. It is ~.002 off of the surface … less than tolerance to be sure but still not a small amount, really - I’ll get this on the heap. The end point appears to actually be on the surface - my know-nothing guess is that is to blame here.