Linux with NextDNS+VPN

I have a problem, after setting up NextDNS on 2 of my PCs running arch linux and linux mint. I've used the resolved.conf file and modified it to use nextdns. And everything works flawlessly except when i try and turn my vpn on. I have this problem on both of my linux machines. I'm using Proton VPN as a vpn client. So basically when i remove NextDNS from my resolved.conf and restart the service systemd-resolved, my vpn works again normally. Any help?