Hi Schoppert,
the /opt/zimbra/bin/zmcertmgr addcacert /etc/ssl/certs/horizon_private_ca.pem did not worked, I eve tried to restart the whole infra with the same result:
COS: Unable to get class of service.
Virtual User: Failed to get list of virtual users
I'm going to try to roll back to a self-signed cert on the gateway to see if the communication with the data works again.
Eric