At one point, the genealogies in Genesis list Korah as a son of Eliphaz, who was a son of Esau. But everywhere else in the Bible, it says Korah was Esau’s son, including several times in that same chapter that says he was his grandson. Also in the first chapter of 1 Chronicles.
Could Esau and his son Eliphaz both have had sons with the same name? Nope. Both of those chapters list the sons of Eliphaz again, and Korah was not one of them.