Fortnite name changes?

My name is Fortnite on example: 05xy28 is my birth month + nickname + birthday. My name is always the same during the game. But in the lobby where you just select everything and can choose the game mode, my name is then only: xy so only my nickname without the numbers. Is that normal?

On which platform do you play? For example, on PS4, your PSN name will be displayed, while your switch's username will appear on the switch. On the PC your normal Epic-name should be displayed ^^

Achso, I did not know, thanks: 'D games on the switch