All Devices using VPN DNS despite only 1 device using VPN client tunnel

[scumball]

Issue with DNS when VPN client enabled

I am using Flint router, on latest version. 4.2.3 Im using mullvad vpn for wireguard vpn client in the router, i have it setup so that only my Virtual machine uses the VPN by mac address, it works well. The issue i see that is somehow is routing the DNS from that vpn client to the rest of the machines that are not using vpn. I went on my other machine and ipleak.net and it shows the vpn ip as my dns, even though my other machine is not using the vpn client. Why is that?