i am posting this so it will be useful to others who have an IPv6 only mail in a box installation with a NATed IPv4.
dns resolved only on 127.0.0.1 but not 192.168.1.100 or ::1 or my public IPv6.
i used “sudo systemctl stop nsd” and then “sudo systemctl start nsd” and when i try an “nslookup” on my domain name, say “example.com” using “nslookup example.com ” it works!
i hope that helped anyone who had a problem like mine.