There is a known issue with upstream datachannel messages and remote AgentHandlers. EEPC/EEMac require upstream data channels during activation. In the logs, I would expect to see entries for sending machine and recovery keys, and then... well... nothing.
Note the mention of EEPC in the following KB article: https://kc.mcafee.com/corporate/index?page=content&id=KB59218
Have you configured your AgentHandler in the DMZ as per the KB article?
Hope this helps,