Any drawing of a planar closed curve don't work at home for me! :)
V4 last december 21 :) idem for previous V4 october!

Idem for V3

I draw a simple curve closed then extrude it without cap!

Idem for no planar closed curve!

https://moiscript.weebly.com/uploads/3/9/3/8/3938813/curiosity_blencap.3dm