Despite Rank Math Pro, thousands of pages not indexed

Hello,

The filter is returning a 500 error because you have a lot of posts and your site’s resources are not able to handle the process. Please use the following filter instead:

function update_focus_keywords() {
    $posts = get_posts(array(
        'posts_per_page' => 1000,
        'offset' => 1000,
        'post_type' => 'post' // Replace post with the name of your post type
    ));
    
    foreach($posts as $p){
        // Checks if Rank Math keyword already exists and only updates if it doesn’t have it
        $rank_math_keyword = get_post_meta( $p->ID, 'rank_math_focus_keyword', true );
        if ( ! $rank_math_keyword ){
            update_post_meta($p->ID,'rank_math_focus_keyword',strtolower(get_the_title($p->ID)));
        }
    }
}

add_action( 'init', 'update_focus_keywords' );

This code will add the focus keyword for 1000 posts at once. Please make sure to increase the offset value by 1000 each time you run the code.

Hope that helps and please do not hesitate to let us know if you need our assistance with anything else.