Round-robin method not load balanced

Seems to me like server2 isn't configured correctly to receive the traffic. You can run a tcpdump to see what's happening with the traffic that's being sent to it. I'm in agreement with Injeyan_Kostas that we would need to know what the health monitor is because the server could be passing a basic healthcheck that verifies a port is listening but nothing at an application level that would mean the server is responding with content.