HTTPS session not passing through F5.

We have HTTPS application using TCP 50001. Certificate is insatlled on the server, not on the F5. For unknown reason we are not able to pass the SSL sesion to the server. When I installed cert on the F5 I can establish the session. The bottom line is we don't want certificate on the F5. Why F5 is not passing HTTPS:50001 directly to the server. I have no problem with HTTP:50001.