Post search not looking at post title since 4.4.2 upgrade

WordPress does not include custom post types in its search by default. You can include specific CPT using pre_get_posts. In your functions.php:

/**
 * Include custom post type in Search
 */

function cpt_include_search($query) {
    if ( !is_admin() && $query->is_main_query() ) {

        if ( is_search() && $query->get( 's' ) ) {

            // add your CPT in the array
            $query->set(
                'post_type', array('post', 'page', 'job'),
                'meta_query', array(
                    array(
                        'key' => 'job_title',
                        'value' => '%s',
                        'compare' => 'LIKE',
                    ),
                )
            );
        }
    }
 return $query;
}

add_action( 'pre_get_posts', 'cpt_include_search' );

Also: make sure your CPT is registered in a way that makes it searchable.
Specifically those 2 lines:

'public' => true,
'publicly_queryable' => true,