This is almost always caused by not updating "saved password" in some software (usually FTP client software) that remembers the old password.
If you keep logging on using a wrong password, then your account will be blocked for a couple hours until you stop logging on. Many FTP client programs remember your password and automatically retrying logon when logon failed. This causes your account being blocked. So please make sure you update all applications that have saved your old password, quit the application and wait for a couple hours.