WordPress Author Link 404

On a search page I allow the user to click a on the authors name to view all posts by that author. Im trying to create the link to the authors page but I keep getting 404’s. However the admin user works. I have checked the user types and they are set authors (Admin is administrator).

Code Example

get_author_posts_url(get_the_author_ID()); 

Result

This returns “/author/tester/” which looks correct since the admin one “/author/admin/” works. However clicking the link goes to 404.

Notes

• This code is executed in a WordPress loop.
• User type is Author.
• Ideally I would like to use the users nickname/display name not actual.