Tasks created by Asana returns null created_by array

Hi!
I’ve noticed that when I send this request:
https://app.asana.com/api/1.0/tasks/{{Task_ID}}?opt_fields=created_by,created_by.name,created_by.resource_type
for tasks created by Asana the created_by response is null. I couldn’t find any documentation on this so I wanted to check if that was normal. When I send this get request for a task GID created by a user it will return their information.
Thanks!