To allow everyone to keep their usernames while also making usernames uniquely identifiable across all platforms, player IDs have been appended to the end of usernames for all players.
You'll be able to find your own player ID attached to your name in your in-game user profile screen.
When viewing leaderboards, we've removed your own ID to make things a bit cleaner, but you'll still be able to see everyone else's full names and IDs.