Extrude extension works incorrectly on circles

Updated repro steps by @jhofinger:

• Create a circle, convert to path
• Duplicate the circle and move it
• Extensions -> Modify Path -> Extrude

The extrude lines are scrambled, some lines connect to nonexistent nodes.

Original description:

I was following this Inkscape tutorial involving the Extrude extension. Unlike the tutorial, which successfully extruded text converted to paths, when I extruded any letters with curves (C, D, G, J, etc.) Inkscape converted any curves to lines.

Attached is a simplified version involving extruding a square path, a star path and a circle path. All paths were duplicated then moved down and to the right, no rotation involved. You can see that the circle's extrusion has reduced curves to lines and also the extrusion points are off-kilter.

Inkscape Version and Operating System:

• Inkscape Version: 1.0beta2 (9d7bad2, 2020-03-08) and Inkscape 0.92.4 (5da689c313, 2019-01-14)(MacPorts)
• Operating System: macOS
• Operating System version: 10.12.6 (16G2136)