Admin Tool WILL NOT Recognize New Passwords

I logged into my admin tool using the default username and password and then I changed the password; then, when I try to log in immediately after doing this, it says "Incorrect Password". I just did the factory reset process which took over 30 minutes to reset usernames and passwords, and I did the same thing again with the admin tool -- changed the password again -- and it saved the password and asked me to log in using that password, and it says "Incorrect Password" again. But it is NOT an incorrect password! I am getting sick of Xfinity.