Can't login WebFig

Hello, I have issue with login to config.
It is ok if I logged in from local ip, but when I connect remotely using public IP, it always say “Authentication failed: invalid username or password.”

Any idea? Or can someone mention why this could happen?

Thanks in advance

Are you sure that you are trying to correct device? Maybe there is NAT rule which redirects you to another device? Is it possible that under System/Users menu for your user is assigned allowed-addresses range?