Please try the following:
Open the original form and insert the field: Custom > Form Bridge.
Then re-apply usage rights and repeat the workflow.
I suspect that the Render operation is failing to augment the form since it is already Reader Extended.
The following documentation has more info on this object. It does not mention your exact case, but it is similar to
Form Bridge object
'You want to certify, encrypt, or apply usage rights to a PDF or XDP form before its first delivery to a user by LiveCycle Forms ES or LiveCycle Workspace ES'http://livedocs.adobe.com/livecycle/8.2/acrobat_designer/wwhelp/wwhimpl/common/html/wwhelp.htm?conte...