Thank you, yes, I've seen some videos and I'm taking my hand.the new sketch calculates constraints on the fly.
if you activate the "permanent" icon then the constraints see them both in the graphic area and in the browser.
_ After the initial shock, I'm getting used to it, and I find it all right. In fact, when I'm from a client with the old sketch I feel like "trapped".
now publish a youtube link with some contributions to understand it better