WebHooks not firing when the event triggered is Workflow post function

In the latest OnDemand version, when a user configured Webhooks to be triggered by using workflow post functions instead of the Events the Webhook seems not to be fired. However, when the Webhoook is configured to be triggered by Event the Webhook is fired accordingly.

Steps to produce:

1. Create a Webhook to fire the events to an external platform
2. Configure workflow pos functions to fire the Webhook instead of using Events
3. Perform the transactions that suppose to fire the webhook

Expected Results:
The webhook should be fired to the external platform

Actual Results:
Nothing is fired.