Dark (Netflix series from 2019)

The time travel rules conveniently mean that they cannot travel to anywhere between 1920 and 1953 since its "present day" takes place in 2019 and the wormhole discovered conveniently only goes 33 years in either direction.

But the real reason I felt compelled to make this post is about the twist in season two where it is revealed that Oops all incest. That's right guy ends up accidentally becoming his own grandpa (literally) and causing an apocalyptic temporal paradox and because of said paradox it is revealed the over half of all romantic relationships in the show are unwittingly incest.