Setting the listen port 8443 to a specific external IP breaks the communication between portal and gateway. This happens because the portal deployer uses a hardcoded target location as "https://localhost:8443". Since the interface listens on an external ip, calls to localhost:8443 fails.
Gateway 10.x 11.x Portal 5.x
Create a clone of port 8443 and set the interface to 127.0.0.1. This allows the listener to listen on localhost:8443
Steps :
2) Clone the "Default HTTPS (8443)" port and set the interface to "127.0.0.1"