With WP Posts Filter you can display posts of certain categories and tags in a page.
I've used techniques that are recommended by WordPress development team for this plugin. Still, there could be some compatibility issues with other plugins used. If you've faced with the plugin malfunction: 1. Turn off (do not uninstall) all plugins but WP Posts Filter and check if it works. 2. (regardless of what you've got in the pt.1) Start a new issue here or here and provide a list of all plugins you have, WordPress version, WP Posts Filter version, results of the pt.1 with the detailed description of a problem. ... and I'll help you.