Hi there @Luc_Van_Cappellen,
You had to set the setting in the Languages menu of WPML and also save it. Then you need to go to Permalinks and set it to be the post name.
I went to your website and did those changes. Now would you please kindly change the admin language to French and then go to Cornerstone?
That should do the trick for the content.
Unfortunately for the footer, there is no workaround at the moment.
Thank you for your understanding.