vmware.hv.status key continued to return 2 (Yellow) for multiple ESXi hypervisors, although the confirmed no corresponding alert or abnormal status in the ESXi side.

After restarting the Zabbix server service, vmware.hv.status started returning 1 (Green), and the related problems were resolved.

This looks like the VMware cache or VMware collector internal state may have kept stale overallStatus values until the Zabbix server restart.