Topic on Project:Support desk

I have created two pages in a MediaWiki: John, and Category:Smith (note that the page Smith is a category page). Both pages were part of the Category:Person. When I run an Ask query to return all the pages that are under the category Person, only the page John is returned. {{#ask: Category:Person | ?label}}. It seems to me that the Ask query does not return pages that are category pages.

Any comment or solution to this problem?

#ask is part of SMW, not core MediaWiki. You should go https://www.semantic-mediawiki.org/ to get support for it.