Can't see the "edit page" button in the section wizard

Hi community !

I'm trying to acess to the edit page button on the section wizard of the page but I can't see it like in the screenshot :

Normally, above the "mini page" title, there is the "edit page" button but I can't see it. I know that some dev's tried to implement something before I came to help them out. I can't see something referring directly to the implementation of this "edit page" button so I don't really see from where the problem can come.

Do you have any idea to help me out ?

Thanks a lot !