Hi hany helmy,
I just wanted to post the solution here for anyone who googles and finds the similar search result. What we found is that the DMV's we pull the metrics from are blank and contain no information. We are an agentless tool and rely on queries to pull the data. So our solution here is to refer back to the original configuration of SQL Server or engage Microsoft services to find why the system tables contain no information / data as without it, we won't be able to pull that information to create our metrics.