SRX not tagging ARP reply packets

Hi Guys,

I have the following config on my srx 300:

ge-0/0/0 {
    native-vlan-id 10;
    unit 0 {
        family ethernet-switching {
            interface-mode trunk;
            vlan {
                members [ vlan-10 vlan-11 ];
            }
        }
    }
}

Most of the traffic is untagged which relies on the native vlan and works seamlessly.

However, with vlan 11, I cannot get it to work. After some wiresharking I discovered a device will send an ARP request tagged with vlan 11 (which is fine), but when the SRX responds, it does not tag the ARP reply so the device in vlan 11 never gets the packet.

Does anyone know why this is so ? is it a bug ? I am running Junos 17.4R1-S2.2 on a SRX-300.