3.1 70bde63 Version on Manjaro.

While drawing stuff my old friend surface problem showed up. This time I documented it a little for any debug use.

Subtractive chamfer on corner drawn from the inside (0,0) worked but did not work from outside (inf,inf).

When drawing the other side also from the inside what previously worked:

But partial is good:

This is inconsistent as the with a little shaking of the point or going in or out of extrusion the red warning disappears. This fuzzy state goes away when the chord tolerance is raised to 0.01 from 0.1 and 10 segs instead 20.
Strange edges it got there too:

The first example lets me think of a failed inside outside detection for surface creation?