Disable Gutenberg For Custom Post Type
If you want to disable Gutenberg for your Custom Post Type (in this example, it is CPT my_cpt), you can use this snippet:
add_filter('use_block_editor_for_post_type', 'cdy_disable_gutenberg', 10, 2);
function cdy_disable_gutenberg($current_status, $post_type)
{
if ($post_type === 'my_cpt') {
return false;
}
return $current_status;
}