Your debug log shows that "named" process is on port 53, which prevents pihole-FTL from using that port.
*** [ DIAGNOSING ]: Ports in use
*:53 named (IPv6)
127.0.0.1:53 named (IPv4)
127.0.0.1:953 named (IPv4)
[::1]:953 named (IPv6)
192.168.2.170:53 named (IPv4)
*:22 sshd (IPv4)
*:22 sshd (IPv6)
*:80 lighttpd (IPv4)
*:80 lighttpd (IPv6)
Typically "named" is BIND9. Find that process on your Pi - these commands may be helpful:
sudo netstat -nltup | grep 'Proto\|:53 \|:67 \|:80 \|:471'
sudo lsof -i :53
kill the process on port 53, then restart pihole-FTL with this command:
sudo service pihole-FTL restart
This should correct the other problem noted in your debug log - the random blocked domain should have returned 0.0.0.0 since you have NULL blocking enabled, but the actual address of the site is being returned.
*** [ DIAGNOSING ]: Name resolution (IPv4) using a random blocked domain and a known ad-serving domain
[✓] fashionjewelryspot.net is 184.168.221.44 via localhost (127.0.0.1)
[✓] fashionjewelryspot.net is 184.168.221.44 via Pi-hole (192.168.2.170)