After rebooting Ubuntu 18.04 Pi-hole doesn’t work until I run the command “pihole restartdns”

If @Mcat12 method dont work, below Ubuntu user had something similar.
Solution in that thread is more like a patch and not really a fix.
If have similar issue, you need to figure out why the interface comes up late (dmesg etc).

And your netstat looks a bit fragmented.
Below how a clean netstat could look like:

pi@noads:~ $ sudo netstat -nltup | grep 'Proto\|:53 \|:67 \|:80 \|:471[1-8] '
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:53              0.0.0.0:*               LISTEN      2957/pihole-FTL
tcp        0      0 127.0.0.1:4711          0.0.0.0:*               LISTEN      2957/pihole-FTL
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      579/lighttpd
tcp6       0      0 :::53                   :::*                    LISTEN      2957/pihole-FTL
tcp6       0      0 ::1:4711                :::*                    LISTEN      2957/pihole-FTL
tcp6       0      0 :::80                   :::*                    LISTEN      579/lighttpd
udp        0      0 0.0.0.0:53              0.0.0.0:*                           2957/pihole-FTL
udp        0      0 0.0.0.0:67              0.0.0.0:*                           2957/pihole-FTL
udp6       0      0 :::53                   :::*                                2957/pihole-FTL

Check for alien config files not belonging to Pi-hole with below one:

sudo grep -v '^#\|^$' -R /etc/dnsmasq.* | sort