Author's posts in a page

I am working on a website for a branch of a political party using Customizr. There is a page for every councillor and I want to display the blog posts by that councillor on the page about them. I want to do it with a page template using the page author to filter blog posts. I’ve tried to do it but although get_author_posts is showing the number of posts by the author, have_posts is returning false. I’m at a loss.