[spoilers s3]Is there a plothole in season 3?

How can Noah or Hanno Tauber exist in Eva's world? Noah is the child of Bartosz and Silja. Silja is the child of Hannah and Egon. But in Eva's world, Hannah does not travel back in time because Ullrich is not stuck in the past because Mikkel never disappeared. So if Egon and Hannah do not meet in the past and conceive Silja, how can she and noah exist in Eva's world?