Solid Extrusion from curve glitch

I am extruding these curves together to create a solid and it’s creating two cylinders instead of a hollow tube.
Also if I go to boolean difference the inside from the outside it leaves me with just an outside surface.
Extrusion Test.3dm (167.9 KB)

Your file tolerance is 0.01, and the wall thickness of the tube when extruded is only around 0.0086 (less than the file tolerance). If you set the file tolerance to 0.001, it works fine.