When I look at the extrude path definition it seems the rendered scene is the expected result. Do you mind explaining in more detail how the final result should look like? Maybe with a screenshot?
Didn’t you see the link in my post !! Check the link Sandbox on my initial post above …
The behavior is not bug is just the way how extrude geometry works with complex path extrusion.So what I did, is a function that extrude geometry following complex path using point projection. I can give you the code if Yu want.