Exit node through linux docker container

I’m using the official tailscale docker image on Ubuntu 22.04 and can’t get it to work as an exit node (from iOS). A Windows computer works fine as an exit node.

I’ve enabled ip forwarding in /etc/sysctl.conf
I use following command: tailscale up --advertise-exit-node --reset

I can access the ubuntu computer using the tailscale IP just fine but I can’t use it as an exit node. I get the following in the docker container output:

tailscale    | 2022/07/29 17:54:32 [RATELIMIT] format("dns: resolver: stubResolverForOS: %v") (30 dropped)
tailscale    | 2022/07/29 17:54:32 dns: resolver: stubResolverForOS: resolv.conf has no nameservers
tailscale    | 2022/07/29 17:54:32 [RATELIMIT] format("peerapi: handleDNS fwd error: %v") (30 dropped)
tailscale    | 2022/07/29 17:54:32 peerapi: handleDNS fwd error: resolv.conf has no nameservers
tailscale    | 2022/07/29 17:54:32 dns: resolver: stubResolverForOS: resolv.conf has no nameservers
tailscale    | 2022/07/29 17:54:32 [RATELIMIT] format("dns: resolver: stubResolverForOS: %v")
tailscale    | 2022/07/29 17:54:32 peerapi: handleDNS fwd error: resolv.conf has no nameservers
tailscale    | 2022/07/29 17:54:32 [RATELIMIT] format("peerapi: handleDNS fwd error: %v")