Hi, I had similar problems when I was doing the tutorial a while back, the main thing I found that can go wrong is that the line lengths are not equal and you get a different number of points on each line, resulting in a null in the final transposed list. If there is a null it won’t place the adaptive trusses, just extend the line in question to get rid of the null. (Or you can reduce the length of the longer lists using slice.)
I also notice that you have multiple Curve.PointAtDistance nodes, you don’t really need to have so many, just hook the List.Create node from the original curves to a singular Curve.PointAtDistance node. This should give you the result you are after.
Also as a test I always use a PolyCurve.ByPoints node to check the curves are running in the correct direction, and there are no unconnected points.
If you ever get a funny result, just insert a Curve.Reverse node to the Curve in question and the trusses should connect correctly.
Hope this helps.