RedirectionSlugs with numbers only in names redirect back to the parent Page

I did not have this problem before I upgraded to 2.5.1.
Right now, all of my pages that have a slug that is made only of numbers cannot be accessed and redirect back to their parent Page.

For example, I cannot access 2007 which is a subcategory of articles:

https://www.invisible-movement.net/articles/

https://www.invisible-movement.net/articles/2007/

I get the first page, no matter what I do. The second page, of course, exists in the admin panel and there was no redirection set.