pfSense

In a fresh 2.4 install QinQ interfaces always show in Status > Interfaces as down even when the parent interface shows as up.
No traffic passes.

QINQ Interface (opt3, igb5_50_25)

Status   down    

igb5_50: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6>
    ether 00:08:a2:09:31:07
    inet6 fe80::208:a2ff:fe09:3107%igb5_50 prefixlen 64 scopeid 0xb
    nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
    media: Ethernet autoselect (1000baseT <full-duplex>)
    status: active
    vlan: 50 vlanpcp: 0 parent interface: igb5
    groups: vlan

igb5: flags=28943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST,PPROMISC> metric 0 mtu 1500
    options=6500bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,VLAN_HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6>
    ether 00:08:a2:09:31:07
    hwaddr 00:08:a2:09:31:07
    nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
    media: Ethernet autoselect (1000baseT <full-duplex>)
    status: active

    <qinqs>
        <qinqentry>
            <if>igb5</if>
            <tag>50</tag>
            <members>25</members>
            <descr><![CDATA[Test QinQ 25]]></descr>
            <vlanif>igb5_50</vlanif>
        </qinqentry>
    </qinqs>