"Last Seen" entry not working (or I don't understand it)

Avast Business Cloud Management Console & Clients
1

It seems like several of our company’s employees machines are not properly sending a heartbeat to avast, because when I see their computers in the “Devices” area, it shows several weeks in the past.

It also appears to happen on my computer, where I can see that:

  1. After a restart, it does update the “Last seen” time.
  2. Some amount of time after the restart (maybe associated to a network configuration change caused by VPN software?) the “Last seen” timestamp won’t update anymore.

So my questions are twofold:

  1. What is this “last seen” timestamp supposed to represent, and is it not working for this case?
  2. If it isn’t working for this case, what do I do to fix it?
2

I might be wrong but I think the last seen indicates the last time the client contacted the avast servers for check for any template changes and report back any status etc. If it is not updating and you are using VPN you need to make sure the client has a gateway route to external internet still while connected. Otherwise the client will probably only update whenever VPN is off.