Why is the workflow step triggering but not appearing in the Action List?

If the workflow step was assigned to an email address instead of the user’s Kuali account like this:

Kuali will treat the recipient as an external user. 

External users do not have an Action List, so the item is only available for them to complete through through the email link provided. 

To ensure future requests appear in the Action List, update the workflow step to assign directly to the user account instead of the email address.