BuddyPress.org

Hiya guys.
Unfortunately, I am having serious problems with a topic seen here every once in a while. I did go through all the posts I could find and tried half a dozen approaches, but none seems to be working.
I am adding notifications to a user when someone is requesting access to a post of that user and so far, everything is fine. The notification shows up in the DB with ID, user id, item_id and secondary_id as well as component_name and component_action.
Now, whenever I receive such a notification, it shows up completely blank.
This is my code:

function request_filter_notifications_get_registered_components( $component_names = array() ) {
 
    // Force $component_names to be an array
    if ( ! is_array( $component_names ) ) {
        $component_names = array();
    }

    // Add 'custom' component to registered components array
    array_push( $component_names, 'project-pitches' );
 
    // Return component's with 'custom' appended
    return $component_names;
}
add_filter( 'bp_notifications_get_registered_components', 'request_filter_notifications_get_registered_components' );

// Formatting custom with respect to action
function bp_request_format_buddypress_notifications( $component_action_name, $item_id, $secondary_item_id, $item_count, $format = 'string' ) {
 		
		if ($component_action_name  !== 'request') {
			return $component_action_name ;
		}
		
		$link = get_site_url();
		$returnlink = $link . "/my-projects/";
    	$request_title = "Test"; /*get_the_title($item_id);*/
    	$request_link  = $returnlink;
    	$request_text  = "abc";

    // New custom notifications
    if ( 'request' === $component_action_name ) {
        
        // WordPress Toolbar
        if ( 'string' === $format ) {
            $return = apply_filters( 'request_filter','Your custom notification for <a href="'.$request_link.'">'.$request_title.'</a> ', $request_text, $request_link );
            $return = "Test";
 
        // Deprecated BuddyBar
        } else {
            $return = apply_filters( 'request_filter', array(
                'text' => $request_text,
                'link' => $request_link
            ), $request_link, (int) $total_items, $request_text, $request_title );
        }
        
        return $return;
        
    }
}
add_filter( 'bp_notifications_get_notifications_for_user', 'bp_request_format_buddypress_notifications', 10, 5 );

Any idea what I might be doing wrong here? Thanks a ton, this is driving me nuts!