Calling related posts to a custom post type, taxonomy & Tag id

by

get_the_term_list() returns HTML but you are trying to use it as if it returned a term ID — 'blog_cats' => $blogcats,. That is not going to work. You will need to use get_the_terms() and a tax_query (I think. I am not 100% sure).

Something like:

$blogcats = get_the_terms($post->ID,'category');
// var_dump($blogcats);

$blogcats = wp_list_pluck($blogcats,'term_id');
// var_dump($blogcats);

$related = get_posts( 
  array(    
    'post_per_page' => 5,
    'tax_query' => array(
        array(
                'taxonomy' => 'category',
                'field'    => 'slug',
                'terms'    => $blogcats,
        )
    ),
    'post_type' => $posttypenews,
    'post__not_in' => array($post->ID) 
  ) 
);