Palo Alto Networks NGFW - ADMIN-ADMIN DOES NOT WORK AFTER FACTORY RESET

The Admin/Admin UserID/Password combination is not working after a factory reset.

After a factory reset, the CLI console prompt transitions through following prompts on a PA-500 before it is ready to accept admin/admin login:

1. 500 login:
 2. PA-HDF login:
 3. PA-500 login:

It is at prompt #3 (need to hit enter to check if the prompt changed), that the device is ready to accept the admin/admin username/password to allow login.