I couldn't find the reliable info on this and I'm confused now. Can you point me to the official source on both sides are same company with slightly different operations?
How do you know that the owner of these platforms is the same person?
There's plenty of proof out there to suggest that 1xbet and 1xbit are probably owned by the same people.
https://bitcointalk.org/index.php?topic=5384944.0Above link is just one piece of proof. You can find more proof by searching this forum thoroughly to find legit links between them. Seems like they all operate under the umbrella of a bigger company basically.