Thecus n5550 nas help

So I just booted up the N5550 for the first time did the setup wizard logged in through the web browser on my PC set up raid but the login prompt in the NAS itself keeps telling me its incorrect it says the default username and password is admin admin in the manual but typing admin in the username area always comes back with "Login incorrect" I did a factory reset to default which worked because I changed the password the first time around and after I factory reset the password changed back to admin. please help!