Rhino 6 Make2D visible lines treated as hidden lines

When I do “make 2D” on Rhino 6, I have a lot of lines that should be visible, being treated as hidden, and vice versa. Doing “make 2D” with hidden lines would still require a lot of rework as the hidden lines include a lot of lines that should be hidden, but are grouped together in the same layer as the curves that should be visible.

I have tried pasting on a new file, increasing tolerance, etc., but cannot solve the issue. I have attached screenshots of the issue.

Hi - this sounds like an issue that we have on our list, but to be sure, please post a 3dm model that we can check.