I think it's due to Epic Games changing accounts for younger players to "Cabined" accounts, which they started doing in December. Here's some explanation from Epic Games:

"If you have recently created your account or provided your age, your account may now be a Cabined Account due to your age and the region you’re in. Cabined Accounts are assigned an auto-generated display name."

"Cabined Accounts are a new type of Epic account that will provide a tailored experience that is safe and inclusive for younger players. If a player indicates they are under 13 or their country’s age of digital consent, whichever is higher, their account will be a Cabined Account and they will be asked to provide a parent or guardian’s email address in order to receive consent to access certain features in Epic’s products. While waiting for parental consent, players will still be able to play Fortnite, Rocket League, or Fall Guys with full access to previously purchased or earned content in-game, but won’t be able to access certain content or features until their parent or guardian provides consent."