Why I can’t change the permalink of this page?

I have the following problem with a permalink: if I open this page (it is implemented as a static page) on my local website: localhost/wordpressAsper/archivio it automatically change it into http://localhost/wordpressAsper/archivio-2/

Going into the administration panel —> pages —> All pages —> Archivio and editing it I can see that the related permalink is http://localhost/wordpressAsper/archivio-2/

So I tried to change it in from archivio-2 to archivio but I can’t because when I confirm the change it return to archivio-2 (but I can change it any other values)

I think that this could depend by an old Archivio page (that I have delete) that had archivio as permalink. So I think that WP have registered the old permalink of the old page (that not exist yet) or something like this.

How can I fix it and have archivio as permalink instead archivio-2. Can I reset the old permalinks in some way?

after you delete a page ,on the “all pages” section, on the top, after the “drafts”, there is link to trash, go there and delete it permanently, after this you can change the slug name.