My gateway login keeps saying my username is incorrect.
I noticed when I click submit my username changes to all lowercase even though I have two uppercase letters in it. Could this be the cause?
By gateway login, do you mean the userid/password for 10.0.01? If you changed the password and you can't enter it again, you may need to reset the gateway to default.
If you have indeed already changed it you will need to set the device back to factory defaults using the recessed reset button on the rear before the above advice (default username and password) will work.