Every time you load a session/start a game those wierd casules appear around the poles for no reason. You have to delete those poles every time or you won’t be able to load/start or even publish. And sometimes those become undeletable, which makes you reopen uefn again and again.
@antosik767 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