Check definition of trigger prototype "Interface {#IFNAME}({#IFALIAS}): Link down" in https://github.com/zabbix/zabbix/blob/master/templates/os/windows_agent/template_os_windows_agent.xml and compare with "Interface {#IFNAME}: Link down" in https://github.com/zabbix/zabbix/blob/master/templates/os/linux/template_os_linux.xml.

The trigger definition is the same even though interface status values are different in both platforms.  2 means Connected for Windows, but link down for linux.

I guess in Windows the comparison should be against 0 (Disconnected) or maybe use a different expression.