It looks like there is some issue with ES, before doing anything I would recommend you to take a cluster backup, config backup and VMware snapshot of vSZ.
Now, there are two options re-index elastic search; I don't have the command on my head right now but if you login to vSZ and in debug mode you should be able to find that command. Run it and this should fix this issue, before doing it open a support ticket and try to get to bottom of this which caused this issue to prevent it from happening in future.
Hope it helps!!