PHP function outside the loop and conditional statement for different post type

I′m using the PHP function to call YARPP posts outside of the post loop, also I use single.php for two different post_types. This is ok?

<?php if (is_singular('rezepte')): ?>
			<?php if(function_exists('related_posts')){
					related_posts(array(
				  'post_type' => array('rezepte'),
				  'show_pass_post' => true,
				  'past_only' => false,
				  'threshold' => 0,
				  'template' => 'yarpp-template-rezepte.php',
				  'limit' => 3,
				  'order' => 'score DESC'
				), $post->ID , true);
			} ?>
		<?php else: ?>
			<?php if(function_exists('related_posts')){
					related_posts(array(
				  'post_type' => array('post'),
				  'show_pass_post' => true,
				  'past_only' => false,
				  'threshold' => 0,
				  'template' => 'yarpp-template-posts.php',
				  'limit' => 3,
				  'order' => 'score DESC'
				), $post->ID , true);
			} ?>
		<?php endif; ?>

The problem is everytime I get the same posts, no matter if I flush cache (yarpp experiments).

Any idea? Thanx.

https://www.ads-software.com/plugins/yet-another-related-posts-plugin/