Hello!
Assuming that in your setup it's the router the device connecting to some VPN server and sharing the VPN traffic with any device behind, please consider that the DNS settings of each device "take precedence". If the device is configured to query Norton Connect Safe DNS, the DNS queries from that device will be encrypted and tunneled by the router (together with all the traffic from that device) and reach the Norton DNS from our VPN servers. Norton DNS will see queries coming from the exit-IP address of our VPN servers.
Kind regards