Auto reply: The plugin is not compatible with Avada in actual version 1.6.9.
I have modified the file /wp-content/plugins/category-ajax-filter/includes/layouts/post/post-layout1.php
adding $caf_content = get_post_meta( $caf_post_id, '_yoast_wpseo_metadesc', true);
after line 33 to get Yoast SEO metadescription.