Custom Post Types and Template Hierarchy

On the following dev site, I set up a custom post type for “Articles”. The post type name is “zu_articles” and the slug is “articles”. Everything is working in the Dashboard and I’m able to generate a listing of articles. But when you click the article link, it goes to a 404. I have the following page created: single-zu_articles.php based on my understanding of the WP template hierarchy.

https://zimmernutrition.com.s137737.gridserver.com/

There is a “Latest Article” widget under the content slider on the right to see everything.

Here is my code for creating the CPT

register_post_type( 'zu_articles',
	array(
		'labels' => array(
			'name' => __( 'Articles' ),
			'singular_name' => __( 'Article' ),
			'add_new' => __( 'Add New Article' ),
			'add_new_item' => __( 'Add New Article' ),
			'edit' => __( 'Edit' ),
			'edit_item' => __( 'Edit Article' ),
			'new_item' => __( 'New Article' ),
			'view' => __( 'View Article' ),
			'view_item' => __( 'View Article' ),
			'search_items' => __( 'Search Article' ),
			'not_found' => __( 'No Articles' ),
			'not_found_in_trash' => __( 'No Articles in the Trash' ),
		),
		'public' => true,
		'hierarchical' => false,
		'exclude_from_search' => false,
		'menu_position' => 20,
		'query_var' => true,
		'can_export' => true,
		'has_archive' => true,
		'description' => "Articles",
		'rewrite' => array('slug' => 'articles'),
		'supports' => array( 'title', 'editor' )
		)
	);

What am I doing wrong?