I opened a ticket with the dev team to check the logs provided by @Camilo Diaz
In case you have the logs (as described by Marcos), or are willing to record them feel free to provide me with them so I can have them checked...
What you have to do is to configure the proxy for both the agent, and the mac security product.
In case the macs are showing not correct "last connected time" it would mean that they are not able to connect to the server at all, which is the thing you should troubleshoot. To confirm this, please check the status.html of one of the mac agents.
Also, what makes me confused is, that you mix topic of proxy and mirror. When you refer to mirror, do you mean actual offline generated mirror by mirror tool, or you utilize the proxy caching function. In this case, you just need to configure both agent / endpoint to communicate via proxy, and they should get the updates from there automatically.
Please note, that in ESMC 7.1 you can configure proxy details for the agent live installer, and also choose a policy that will be applied to the machine.
@Marcos can you please move this to "ERA" portion of the forum?