define custom link in custom post type not working

I have a masonry grid showing posts from multiple post types. At least 1, maybe 2, of the custom post types need to directly open the defined custom link in a new page. I have added the necessary code to the meta.php file to recognise the CPT’s and added the following code to the functions.php so that the additional portfolio settings are visible in the CPT builder page:

add_theme_support('add_avia_builder_post_type_option');
	add_theme_support('avia_template_builder_custom_post_type_grid');
	add_filter('avf_builder_boxes','yanco_enable_cpt_layout_builder');
	function yanco_enable_cpt_layout_builder( $boxes ) {
		$boxex = array();
		$boxes[] = array( 'title' =>__('Avia Layout Builder','avia_framework' ), 'id'=>'avia_builder', 'page'=>array('post','portfolio','page','product', 'enfold_repeatable', 'pdf', 'instagram'), 'context'=>'normal', 'priority'=>'high', 'expandable'=>true );
	    $boxes[] = array( 'title' =>__( 'Layout','avia_framework' ), 'id'=>'layout', 'page'=>array('post','portfolio','page','product', 'enfold_repeatable', 'pdf' ,'instagram' ), 'context'=>'side', 'priority'=>'low');
	    $boxes[] = array( 'title' =>__('Additional Portfolio Settings','avia_framework' ), 'id'=>'preview', 'page'=>array('portfolio','post','pdf','instagram'), 'context'=>'normal', 'priority'=>'high' );
	    $boxes[] = array( 'title' =>__('Breadcrumb Hierarchy','avia_framework' ), 'id'=>'hierarchy', 'page'=>array('portfolio','project_archive', 'pdf', 'instagram'), 'context'=>'side', 'priority'=>'low');
		return $boxes;
	}

However, when i define a custom link on a CPT post, it does not link to the url, but instead links to the blank post page. Please could someone let me know what i have missed?

Thanks,