Enable custom post type WordPress preview. Source: https://woorkup.com/wordpress-custom-post-type/

wordpress-preview-cpt.php

//adds custom post type query var to preview links
function mycptname_cpt_previow_query_vars($link, $post) {
	$custom_post_types = array('artist');
	if(in_array($post->post_type, $custom_post_types)) {
		return add_query_arg(['post_type' => $post->post_type], $link);
	}
	return $link;
}
add_filter('preview_post_link', 'mycptname_cpt_previow_query_vars', 10, 2);