Paulius
Firstly thank you very much for your repsonses and help on this :D.
So I believe the routing is fine as I can telnet to the backend server on port 8443.
telnet 10.110.64.155 8443
Trying 10.110.64.155...
Connected to 10.110.64.155.
Escape character is '^]'.
So you believe it could be the server dropping the connection?
The above telnet proves that connectivity and routing to the device is configured correctly and there is a permit on the firewall that allows it.
That also confirms that the server is listening on port 8443, I've hit a stumbling block.
I am not sure, I tried to recopy the syntax you provided and modified it on the F5, must of left an extra space somewhere 😄