/opt/vmware/var/log/vami/updatecli.log last entry shows... "Updating repmgr DB schema; invoking: /opt/vmware/appliance/bin/update-repmgr-db.sh".This can occur if the standby cells are upgraded prior to the primary cell.
Please see the following documentation for reference.
Upgrade Your VMware Cloud Director Appliance by Using the VMware Update Repository