mongodb connection string through the LTM virtual server

We need to migrate data from a cloud service to our mongodb server so it can migrate its db to our mongodb. We created a vip 172.19.200.114:27017 with one pool member 172.19.48.176:27017.

When we use robomongo to test the connection we can connect and authenticate via the pool member but if we try it through the vip ip it times out. This is wireshark showing the tcp handshake, then the mongo protocol with a query but no reply... But if we test the connection through the server directly it connects all the way through... We are pretty sure the vip is set up correctly because if we navigate via Chrome to 172.19.200.114:27017 or 172.19.48.176:27017 we get this in the browser: "It looks like you are trying to access MongoDB over HTTP on the native driver port." That makes me think we get the traffic all the way through the LTM so I'm not sure why the connection string isn't able to connect to the vip.