The problem is that the remained circle is not displayed at all.
For example, drag & drop the curved stock from the sheetmetal catalog,
and then select the Edit Cross section. And then draw the circle(any circle;
center radius, 2 points,...) as the above fig.
And then clcik the Trim curve icon at bottom, and click 3 of the above fig to
trim off that part of circle.
Then the remained part of the circle(number 2 in above fig) is disappeared.
But if we move the mouse to this part, then we could see that this remained
part(2) is still there but not displayed.
(If I use the curve or arc instead of circle, then the remained part of these
curve and arc are displayed after the trim off. So I could see if the cross
section is correct or not before to click finish.)
The problem I pointed is that the remained part of the circle after trim off
should be displayed.
For your reference, even though the remained part of the circle after trim off
is not displayed, it is still there. So if we click the finish button, then the
remained part of this circle became a crsoo section and visible.
JH