Redundant OPC Server Connections

I tested a system like i metnioned above and it works, if the Master is shutdown, the secondary FactorySQL Service and OPC Server takes over.

But i was not able to make the following scenerio work:-

I have 2 servers, both with 1 FactorySQL and 1 OPC Server.
The OPC Server is the same with the same topic and tags
The FactorySQL project has redundancy enabled between these two servers.

If OPC Server Goes down on the Master Server while the FactorySQL Service is still running, The Secondary doe not take over.

I tried using OPC Quality Tag in redundancy also and only stopping the OPC Server on the Master Server, still the secondary did not become Active. Please advise.

What I want is that IF OPC Server on one of the FactorySQL Server goes down, the switchover should take place to a server where both FactorySQL and OPC Server are OK