Task Item added event receiver does not fire when item is added by Nintex workflow SharePoint 2016

I am trying to add an event receiver on the workflow task - list Item Added event, to get the Task ID and update it on another SharePoint List.

This is because once I add an Assign Flexi Task action on the Nintex workflow, there is no way to get the created task ID in the workflow, unless someone actions on the task.

However, the Event Receiver on the Workflow Task list Item Added event does not fire!?

Can someone help me in solving this? or any alternative solution please.