Can’t argue about coincidence… LOL… but I’d have to say I find it a bit unlikely that they would cut you off just like that.
One way to get a hint is to check the daily activity of the group, then of each casino – and then do the same for the previous months – then you can see where the activity stopped.
If it stopped at one casino, or slowed down, you’d be able to pinpoint a possible problem.
If, however, the entire group showed a dramatic shift, you’d certainly have grounds for a major issue – exactly what issue, I don’t know.