Send Notification after post published was working but stopped after the last WP update

Question

I'm just wondering why this snippet stopped working! It was working before the last WordPress Update!

I'm using DW Notifications plugin and work without any problem in another functions.

There are any explanation, Thanks.

function to_followers_only_notify( $new_status, $old_status, $post ) {

    global $post;

    if ( 'publish' !== $new_status or 'publish' === $old_status )
        return;

        $post = get_post($post->ID);
        $author = $post->post_author;
        $author_name = get_the_author_meta( 'display_name', $author );

        $followers = get_user_meta($author, '_pwuf_followers', true);
        $followers = array_unique($followers);

        $title = '<strong>'.$author_name.'</strong> ' . __('Published new post', 'dw-notifications'). ' <strong>'.$post->post_title.'</strong>';
        $link =  get_permalink($post->ID);
        if(has_post_thumbnail($post->ID)){
            $image = get_the_post_thumbnail_url($post->ID, 'hitmag-list') ;
        }

        $notif = array('title'=>$title, 'link' => $link, 'image' => $image);

        if ( !empty( $followers ) && is_array( $followers ) ) {

            $follower_ids = array();
            foreach( $followers as $follower ) {
                if ( is_numeric( $follower ) ) {

                    if(!$post->post_author || $post->post_author == $follower) continue;


                    $follower_ids[] = $follower;

                }
            }
            dwnotif_add_notification($follower_ids, $notif);
        }
}
add_action( 'transition_post_status', 'to_followers_only_notify', 10, 3 );

Update 1

When I used publish_post action back to work again! But I need to avoid from everytime posts updated :(, any suggestions please, Thanks.

function to_followers_only_notify( $ID, $post ) {

    global $post;

        $post = get_post($post->ID);
        $author = $post->post_author;
        $author_name = get_the_author_meta( 'display_name', $author );

        $followers = get_user_meta($author, '_pwuf_followers', true);
        $followers = array_unique($followers);

        $title = '<strong>'.$author_name.'</strong> ' . __('Published new post', 'dw-notifications'). ' <strong>'.$post->post_title.'</strong>';
        $link =  get_permalink($post->ID);
        if(has_post_thumbnail($post->ID)){
            $image = get_the_post_thumbnail_url($post->ID, 'hitmag-list') ;
        }

        $notif = array('title'=>$title, 'link' => $link, 'image' => $image);

        if ( !empty( $followers ) && is_array( $followers ) ) {

            $follower_ids = array();
            foreach( $followers as $follower ) {
                if ( is_numeric( $follower ) ) {

                    if(!$post->post_author || $post->post_author == $follower) continue;

                    $follower_ids[] = $follower;

                }
            }
            dwnotif_add_notification($follower_ids, $notif);
        }
}
add_action( 'publish_post', 'to_followers_only_notify', 10, 2 );

Answer 1

Regarding Update 1. Perhaps you could compare the publish and modified dates and run your code only when they match, i.e. when the post is first published. Something along these lines,

function to_followers_only_notify( $ID, $post ) {

  $posted = strtotime( $post->post_date );
  $modified = strtotime( $post->post_modified );

  if ( $posted !== $modified ) {
    return;
  }

  // rest of the code
}