Setting up Onboarding Event handlers for Template assignment

We are implementing Onboarding and utilizing template assignment rules. As a part of this, we noticed that there is a Event associated with triggering Onboarding template assignment. Under Enterprise Components > Events & Notifications > Event Framework > Event Registry we activated Onboarding event handler under Assignment Added event. We are utilizing delivered configuration.

After Manage hires process, Onboarding trigger is not being triggered. Is there any additional configuration that I need to check? I do not see any errors in trace file. I also enabled logging and trace file on the event and handler, I do not see any helpful information. I would appreciate any insights.