Sophos Web Appliance - Load Balancing not working properly

Hi There,

We are trying to enable the Load Balancing in Sophos Web Appliance, but it is not working properly.

We have 3 Physical and 2 Virtual Web appliances.

Note: Appliances in Load Balancing are in Transparent mode.

Load Balancing between 2 Virtual appliances works fine. But it is not the case between Virtual and Physical Web appliances.

When the traffic is routed to the Management appliance from the Firewall, traffic is then routed to the attached appliances via Virtual IP, we don't see a problem when the traffic goes to the virtual web appliance, but when the traffic goes to the physical web appliance, the port number is changed automatically and we couldn't figure our why. 

Would appreciate any help.

Thanks in advance.