We just had three weeks full of igaming conferences and you could see everyone mingling with... well, everyone.
Now, I can't say for sure that the platform and operator aren't owned by the same people due to logo similarities, but I know for a fact that sharing booth costs or promoting your providers on that booth is a common practice.
Bet-b2b is based in Cyprus, 1xBet is based in Cyprus, and both of them have headquarters in Limassol. Keep in mind that the creators of 1xBet are Sergey Karshkov, Roman Semiokhin and Dmitry Kazorin, three Russians who are put on the International Wanted List by the government of Russia. Also, keep in mind that they flew to Cyprus to escape.
Is this a coincidence? I don't think so, especially when we know the shady past of 1xBet and if we also consider that too many scam projects use Bet-b2b CMS. Also, as far as I know, 1xBet is the first casino of bet-b2b.