Filter not doing anything?

I created this filter, it does not seem to do anything. It is in a custom plugin for the site, which contains other functions that are confirmed working. I am using FeedWordPress 2025.1211 on WP 6.9, PHP 8.3.30

function strip_nbsp_from_feed_titles($title, $post) {

$title = trim(str_replace(' ',' ',$title));

return $title;

}
add_filter('syndicated_item_title', 'strip_nbsp_from_feed_titles', 10, 2);