[Plugin: WP Download Codes] Download link populates but links to Apache2 page

The plugin work correct form start to finish when using the full link such as https://mydomain.com/downloads/?yourcode=download1234 but when I link to the download code page and ask users to enter their download code it populates the download link correctly but when clicked goes to a Apache2 index page.

Any help would be greatly appreciated. Love the plugin!