Help: Cannot connect through firewall

Can anyone offer suggestions on this problem? I’'m unable to connect any clients successfully to Wildfire through a firewall from the WAN. On the LAN it is working fine.

The Wildfire log error shows “connection closed before session established”. Other information:

=The error happens with both plaintext and SSL.

=I’'ve tried this with both Exodus and Psi.

=Inbound 5222 and 5223 are open on the firewall and mapped to the WF server.

=I’'ve tried with both 2.6 and 3.0.0 beta.

=IP allow list in WF is open for everything

Several archived postings on this issue seem to point to naming on the server and/or client as the possible source, but I’'ve tried all the possible combinations of IP number-names and DNS names I can think of without any change in the problem.

Thanks for any suggestions