I just installed MediaWiki 1.27.1 and setup completes without issue on a server with Ubuntu 16.04, nginx, PHP 5.6, and MariaDB 10.1.
I created an export file with a different wiki using the Special:Export page. I then imported the articles to the new wiki using the Special:Import page. The file size is smaller than any limits and time the operation takes to complete is much less than configured timeouts.
Before import, I have created articles and categories and everything works as expected.
However, after importing, when I create a category tag on an article, clicking the link to the category's page doesn't show the article in the category.
I am using this markup within the article to create the category:
Is this a bug or am I missing something?