cut-extrude thin not detected, defaults to "through all" in both directions

when i create a sketch with open contour for a cut extrude-thin, the following happens:

1) create sketch with an open contour (ie: a single line)

2) try to cut-extrude, SW asks if i want to close the sketch, i click no

3) then instead of detecting extrude-thin, it defaults to "through all" in direction 1 and 2.

4) every single time i have to check "thin feature" then un-check direction 2, then change direction 1 from "through all" to "blind"

does anyone know why this happens?  am I missing something, why would cut extrude-thin default to that?

another note, boss extrude thin works properly, auto detecting a thin feature when an open contour is extruded and defaulting to blind instead of through all.

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