Are you sure it is a numbered list? It looks like a bullet list.
You have an error in the settings of the dialogue box.
In the field labeled Numero: you have .^t (period, carrot, t which creates a period followed by a tab).
Change that to: #.^t (pound sign, period, carrot t). The # generates the number in the list.
It is because you have deleted the autonumbering metacharacter (^#). See my screen shot
Try these settings. The important point is the list level (“niveau” in French), on the right of the screen shot
Anyway, you need more than one paragraph style since you have black regular text, black bold text and red bold text…
Yes, thank's a lot!