Dynamic VPN secondary DNS issue

Hi all,

We're having an issue with our dynamic VPN secondary DNS allocation to clients.

The configuration is as follows :

family inet {
    network 192.168.10.0/24;
    range range-XXX{
        low 192.168.10.200;
        high 192.168.10.205;
    }
    xauth-attributes {
        primary-dns 192.168.0.100/32;
        secondary-dns 192.168.5.52/32;
    }
}

However, when a client connect, only the primary DNS is attributed. Secondary DNS is ignored. This happens on both Windows 7 & Windows 10 clients.

Any help on this issue would be hugely appreciated.