OpenVPN Connect, SSL VPN and Sophos SG125 DNS problems

[masterx81]

Hi!
I've setup with a Sophos firewall model SG125 an SSL VPN, and i'm using openvpn as client.
All works as it should, the connection works well, i get the correct ipv4 address. The problem is that i get some weired ipv6 DNS servers addresses (fec0:0:0:ffff::1%1, fec0:0:0:ffff::2%1, fec0:0:0:ffff::3%1), while must be ipv4 (and on the firewall the ipv6 addressing is disabled).
I've tried using Sophos connect as client, and with that software the DNS addresses received are correct, so the firewall is correctly configured.
I've also tried editing the settings of the open vpn connect client, also those the advanced settings, with no result.

What i need to check to get the correct dns ipv4 addresses sent from the firewall?

Thanks!