min curve radius error but curve checking tools says else

hello
I want to make a sheet metal part and form it with a forming tools , this is a training project.
when i insert it in flange , this error appear "The part's thickness may not be compatible with this form tool. The thickness must be less than the minimum radius of curvature for the form tool. "

i used "check tool" in "evaluate" menu and see that the minimum curvature of forming tools is greater than the flange thickness . and this wondered me!

i attached files...

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