Sweep1 training, why is it twisting?

I’m working through the level 1 training, exercise 11-6 using sweep1. On the third section with 3 curves and a rail, when I follow the steps in the manual the sweep produces a twisted surface between the curves which is not how it looks in the manual. I’m seeing immediately how to fix this to get it to look right. Here’s a couple screenshots of how it looks. What am I missing here?.

Screenshot 2024-05-05 213855

Screenshot 2024-05-05 214619

Well, of course, as soon as I post this I figure it out. I was selecting all four curves before activating the sweep1 command. When I activate the command before selecting curves and then select the rail first then the three curves it comes out right. The training manual does say to select all four curves before activating the command so I wonder if this is a bug?

Screenshot 2024-05-05 215924

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Select the curves by first clicking the rail and then the sections, it works on my end.

With window selecting the curve order might be off. The command could probably guess which of the curves is the rail and which are sections…

FYI, window selecting the four curves, the result looks the same in Rhino 7.

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[BUG Report] - Offset & Loft, Incorrect Numbering - Grasshopper - McNeel Forum

Update to 8.7 Maybe its fixed, could be this Bug

How is this related to Sweep1 in Rhino, not Grasshopper?