I feel like the comments are archanment, from what I've seen 1xbet has caused a lot of problems for its users I've never been one of them so I don't know, BUT 1xbit I've been there since August 2018 never any problems...
There is no difference between the two sites. Essentially, both sites run on the same platform and are owned by the same company, but are under different domain names. 1XBit is an unlicensed version of 1XBET to circumvent various countries' restrictions. In fact, all the problems you mention really come from the 1XBET security department that handles payouts. So-called "support" from 1xBit doesn't have any control over them.