If you change the island settings, the session will fail. Specifically, you won’t be able to start or end the game from the Fortnite screen, and you won’t be able to change island settings.
If you experience the same phenomenon, please comment. Also, if you know the solution, please let me know.
@Pruflas000 Thank you for your report! We would like to look into this further, would you be able to submit a bug report using the form available here: Fortnite Creative