One user is reporting his email address being displayed in community instead of his name (I will avoid linking him here since it's a privacy issue). @Piotrek Romanczyk [SoftwarePlant] has updated his username with his company name, but is reporting it hasn't yet synced.
If you're having issues syncing or updating your username, can you report them here? It will help us troubleshoot.
Update: Logging completely out of your Atlassian account and back in again will re-sync your account and should resolve this issue. Please try this solution and let us know if it doesn't work.