A few day ago several Domain Controllers were rebooted after a Windows Updates.
The day after some Primary servers were also rebooted.

Since that, several users call the helpdesk because they were disconnected from Agent. If they reconnect then it sometimes work but if they do a zac ref then sometimes the agent is still disconnected again.

We managed to reproduce the problem on some workstations. These workstations were rebooted but the problem remains.
All DC and all PS are up and running.

Do you think there could be a relationship between the servers reboot operation and this problem?