Problem solved.
I moved a dimension and mtn, my extrusion is straight...
I put it back as before and tjs ok.
TADAM magic hat
The night brings advice to SolidWorks too?
@fthomas
I had used check and no errors to report.
A little more subtle, I selected what I saw but if I hovered the mouse without selecting, I saw what I wanted.
@gt22
If you don't understand, it's because you haven't had the opportunity to draw parts for molding/injection.
Or that I have trouble expressing myself
Look at the attached file and compare the 2 volumes with the tree.
Is it clearer?
Congé83 was sabotage :-)
I had tried to put a leave on the problem edge to see his reaction.
NG result.
The orange lines off volume were the result of the function as I was supposed to have it.
Without an oblique edge.
Thank you all for the support.
It was probably a bug but how...
test_conge.sldprt