Strange results when running ContinueCurve

When I run the ContinueCurve command, random control points seem to be displaced by an arbitrary vector. Is anyone able to recreate this issue?

ContinueCurve.3dm (2.8 MB)

Hi Ryan - I see that, thanks. For now, Explode and just continue the end bit - the thing is not really designed for rational curves, I guess is the problem. I don’t know how easy it will be to tune up…