Hide current blog post from a random blog post slider grid element

I have found a few similar threads in the forum trying to solve this issue, from which I have tried the following codes to no avail:

add_filter('avia_blog_post_query', 'enfold_customization_query_custom');
function enfold_customization_query_custom( $query ) {
global $wp_query;
if ( is_single() ) {
$query['post__not_in'] = array($post->ID);
return $query;
}}

/* also not working */

add_filter('avia_post_grid_query', 'avf_custom_post_grid_query');
function avf_custom_post_grid_query ( $query ) {
  if(is_singular()) {
  	global $post;
  	$query['post__not_in'] = array($post->id);
  }
  return $query;
}

I am not sure if the problem is due to the post type being a custom post type called ‘knowledge_articles’ instead of posts? If anyone could shed some light on why the above code is not working, it would be much appreciated.

A link to one of the blog posts is in the private content, but please note the posts display randomly, so you may need to refresh a few times before seeing the current post within the blog post grid.

Thanks for your help.