Trigger activity set based on mandatory task of the previous activity set

[Skydev22]

Hello Community, I have a requirement where I need to trigger an activity set when all the mandatory tasks (optional = false) in the previous activity set are completed. Here is what I have done in the advanced trigger, but it still isn't working. Anyone can help with this, please? 

(function shouldActivitySetTrigger(parentCase /* GlideRecord for parent case */ ,

    hrTriggerUtil /* hr_TriggerUtil script include instance */ ) {

    var grTask = new GlideRecord("sn_hr_core_task");

    grTask.addEncodedQuery('parent.sys_id='+parentCase.sys_id.toString()+'^optional=false^sn_hr_le_activity.ref_sn_hr_le_activity.activity_set=b525e12f335c5e1074abc1c13d5c7b46');

    grTask.query();

    while (grTask.next()) {

        if (grTask.state != 3) {

            gs.info("Required task still open: " + grTask.number);

            return false;

        }

    }

    gs.info("All required tasks completed for case: " + parentCase.number);

    return true;

})(parentCase, hrTriggerUtil);