After Destiny 2 received a routine update recently, an issue spread among players in which the username was changed to a generic name, which is the name Guardian attached to four random numbers, with players receiving a message stating that the name was changed because they were logging in for the first time or because they decided to change the name, which of course was not requested by the players.
Bungie has confirmed that it is aware of the issue and is investigating the cause and will share more details as soon as possible with players providing a way to rename their account, but it is currently unclear whether players will be able to restore their original account names.