post_exists returning 0 if title contain special characters

Looks like WP is using HTML entity encoding on the special characters, you need to parse the title using the html_entity_decode() function like so.

$title = html_entity_decode(get_the_title($result->post_id));

if ( 0 === post_exists( $title ) ) {
$title="Document Id: ".$result->post_id .' (Deleted)';
}

I am not sure if the post exists function decodes the characters but I am going to assume it does, let me know if you are still getting a 0 though

Comment below any questions!