Search “Post types” of only selected taxonomy, does not work.

I have four post types divided by “Taxonomy: Tipologie.”
When they expire the “Old Tipologia” is added, either manually or with PublishPress Future.
On one page I need to search for posts only among those that possess the “Old” as a Tipologia.
I set “Search “My post types” of only selected taxonomy=”Tipologia: Old”, but when I try, Ivory Search also shows posts without the “Old Tipologia”, without any distinction.
Is it me making a mistake or is there something wrong?
Thanks