Thanks. My copy-paste was the wrong.
$form ='[mb_frontend_dashboard edit_page="494"]';
and in ID = 494 :
[mb_frontend_form id='projet-field-group' post_fields='title' "]
But the bug is confirmed (it worked with 1.11.7 and not with 1.11.9).
The Dashboard button "Add new" works but not the listing.
-> You have 0 posts.