In my firewall I did not enabled the ipv6 to any port. But still firewall releasing the ipv6 IP address to the devices like Mobiles and IPV6 enabled systems. I am unable to trace where it is releasing and why. Could you please any one help in this regard.
Make sure you also didn't configure IPv6 DHCP server on the XG. Also, how are you checking if the XG is the one providing the IP?