[Closed] Problems With `comment_post` Hook

Hello. I've been trying to echo a message after comment is posted and tried `comment_post` action that comes with Wordpress, but the message is not echoed on the screen. Also, when the action is registered and a comment is posted, the loader animation shows up but the comment doesn't become visible in the comment list. I can insert into database with that function and hook successfully, but echoing, returning or redirecting doesn't work. I've even tried functions that are confirmed as working, but no luck in echoing anything. I've also tried `wp_comment_insert`action, but I have the same issue. Insertion to database also works with it.