We recently upgraded from ISE 1.4 to 2.1 an applied Patch 3. We have a 2-Node Deployment. Since the upgrade, the dashboard metric for Active Endpoints and Authenticated Guests are blank showing zero. I have TAC case open, but was wondering if anyone else has ran into this issue.
We had to generate new admin certificates for each node in the deployment.
Admin-->Certificates-->System Certificates-->select your node-->generate self signed cert --> and then in the SAN field of the form put in the IP address of that node.
I had run into that bug a few times. There has not been any issue since redoing the certs.