We’re aware of issues when managing Fortnite Creative islands via the new Creator Portal. We are working hard to fix this now, and will let you know when we have more info.
You’re still able to publish Fortnite Islands via the game interface, and we can’t wait to see them.
Good news! You can now publish your Fortnite Creative maps using http://create.fortnite.com. This includes submitting to Discovery. The next time you publish from Fortnite Creative, you’ll see your private version appear in Creator Portal.
Be sure to restart Fortnite so you are directed to the correct publishing flow. Thank you!