You can clone with
No one assigned
Creating a Task using Webworks and then opening the same task with the Tasks app, will show that there is something different with the Task:
Even if I assign a recurrence at the time of creating the task, it still does not show up.
PS - If i assign some recurrence to the task in the code, and then try to delete the task in the tasks app in asks me if I want to delete just that task or all in the series. It means the recurrence is saved, but somehow it just does not show up.