IPv6 DNS Leak

RiseupVPN version: 0.21.11

Distro: Fedora 41.4

Kernal: Linux 6.11.7-300

I have installed the RiseupVPN snap package but it seems to be leaking DNS. 

the resolvectl command shows no DNS server is configured under tun0:

Link 6 (tun0)

    Current Scopes: LLMNR/IPv4 LLMNR/IPv6

         Protocols: -DefaultRoute LLMNR=resolve -mDNS -DNSOverTLS

                    DNSSEC=no/unsupported

And only my normal dns server under wlp1s0.

Using https://www.dnsleaktest.com/ shows my ISP

The defaul resolver in Debian doesn't use systemd-resolver, so this is probably not tested/broken on Fedora? A short search shows this: https://forums.fedoraforum.org/showthread.php?329090-Set-DNS-Permenantly-For-VPN&p=1862012

Not sure how to move forward here.

I will also add that I have tested it on Linux Mint 21.3 now too (also using the snap package and version 0.21.11) and I have the same issue there. It used to work for me but I have not used it in over a year so I don't remember if I did anything differently.

In case I am installing it incorrectly, these are the steps I used to install it:

on fedora: 

sudo dnf install snapd

reboot

sudo snap install --classic riseup-vpn

on mint (with snap already enabled and snapd installed): 

sudo snap install --classic riseup-vpn 

Doing further testing, it is leaking specifically through ipv6. Disabling ipv6 resolves the issue, though is not an ideal solution. My modem does not have an option to disable dns over ipv6 and I don't want to disable ipv6 entirely so I would have to do this on each device that I plan to use the VPN.