As you are not the rep, they will not disclose anything to you. Many people had similar problem, I would recommend to send the rep form via webform.Nope, this is for my parents.
It seems like I need the application number to link the app? Otherwise, the primary applicant has a middle name, and I'm not sure how the system would ask for it. I tried multiple combinations, but couldn't get the right combination I think
Try the ecas from the below link with your old or their old UCI#. You only need the surname.
https://services3.cic.gc.ca/ecas/security.do?lang=en