Hi,
please disable the DNSmasq DNS first because it conflicts with Samba on the same node as both want to use the same ports.
it seems you didn’t enable the file server (which includes authentication, see User domains | NethServer 8 documentation) as the Samba server has a wireguard VPN IP 10.5.4.1 which isn’t reachable from LAN.
I assume there’s just one NS8 node and a single samba server without replicas. In this case it’s possible to change the IP to the LAN one - 192.168.16.7:
api-cli run module/samba1/set-ipaddress --data '{"ipaddress":"192.168.16.7"}'
Now the DC should be reachable from the clients.