I have the same problem, have followed the steps carefully with the various detailed options (UCI or application number, spaces after name etc). Is there a time lag from receiving the AOR and being able to link?Any of you can link an application as long as you have GCKEY, but, you need the applicant's details (UCI, Last name etc) to search for the application.
See the steps here:
https://docs.google.com/spreadsheets/d/1Gm315tmNKWoywb7PwZBiE67fUmznYQrNhYVWXPXXJBw/edit#gid=2037240319