Setup:
1 nic in server active (4 built in but only using 1)
1 loadblancer TP-Link 480+
3 x Fritzboxes for the ADSL connections

Confirmed working:

• We successfully saved with War Room a while ago
• Players can connect to any external IP and play on the server

IF the above mentioned IPs are definitely correct, then it's a routing or a map problem. Can you confirm that?