Add a canvas panel to child of Scroll Box

Hy,
I’m trying to add a widget, which contains some text and some buttons, as child of a scroll box.

This is how I create the main widget :

Then I create all other widget I need and add them as child :

When I execute the game, all nodes are reached but I can’t see anything in my scroll box…

I succeed to do it with only button in child widget, so is this possible with a canvas panel or am I missing something ?

(Sorry if I made mistakes with english, french writer)

I succeed to do it with a grid box instead of canvas panel, I can’t understand how it works because first time I did it with canvas panel, anyway it works like that if someone need this information !