Disable Tailscale DNS
The fix is to tell Tailscale to stop managing DNS on this machine:
tailscale set --accept-dns=false
Then set your resolv.conf manually:
echo "nameserver 1.1.1.1" > /etc/resolv.conf
echo "nameserver 8.8.8.8" >> /etc/resolv.conf
# Optional if the server is on your home LAN:
# echo "nameserver 192.168.2.7" >>> /etc/resolv.conf
Then test:
ping -c 3 google.com