Two things to share:
1) I emailed John Low, who handles IR for Zuoan about the dividend status and received this reply
We confirm we have made the payment transfer to the depositary bank, Deutsche Bank, for on-payment to all ADR holders. As we have no control over the internal processing time at Deutsche Bank or your broker, I would advise that you contact your broker to check on payment progress.
2) I contacted my broker (TD Ameritrade) and was told that the dividend payment has already been received, but that the ADR payment would occur on June 20, as there are extra steps involved
So, it appears that we have only a delay and not a serious issue.