Problem with Elgg Group Subscriptions

I am having a strange problem with the group subscription in Elgg. Not sure whether its a bug. So thought of first posting it here.

Have an Elgg install of Version 1.11.2 with only group, profile and notification plugins enabled. I am trying to create groupforumtopic via a simple script which has to be run without the user login. So I wrapped everything with in elgg_set_ignore_access() as below. But when I run this script, no group subscribers are getting notified about the new topic. If I create a topic after loging in, then the users are getting notified. Am I missing / overlooking something?

<?php

    require_once(dirname(__FILE__) . "/engine/start.php");
    
    $ia = elgg_set_ignore_access(true);

    $topic = new ElggObject();
    $topic->subtype = 'groupforumtopic';
    $topic->title = "Title";
    $topic->description = "Description";
    $topic->status = "open";
    $topic->access_id = 2;
    $topic->container_guid = 59;
    $topic->owner_guid = 37;
    if ($topic->save()) {
        echo "Topic created";
    }

    elgg_set_ignore_access($ia);