username generator one word - Greenn Stage
The point of my answer is that submitting password in the username field could result in the exposure of the cleartext password in places where it can be seen by other people, including well intentioned admins or malicious actors who managed to get access to logs or backups where logs are stored, etc. The username is only truncated if you are linked to a Microsoft Account. So, the easy solution to this problem is to unlink the Microsoft Account, when prompted for a username enter the full username you wish to use.
Understanding the Context
Once you logout of the profile and log back into the profile, the user's profile directory, will reflect the name you entered in the prompt. At that point you can link the user to ...
