EB-3 Visa

I applied for EB3 (unskilled worker) visa in 2016. The LC was issiued and everything needed was prepared and passed USCIS assesmenent and issuance. It was sent to NVC for further processing and by the time my documents arrived in the US for onward application, the case had been recalled to USCIS for review. It has ben there since Nov 6, 2017 without any information as to what is happening. I am from Ghana but live in China where I applied from with my wife.

Could anyone let me know from experience if this means a denial. If not, what is the chance of approval? It seems a bit strange since it has been recalled by the same office that approved it. I am thinking of cancelling it as I do not know when it could be approved, if any, considering my age (45).

Furter question: I was told by my agency that once immigration visa has been applied, no other visa applican can bemade unless the previous case is closed. May I know if it is true.

Thank you.