gtw: 192.168.0.2 ZS
(initiali I suggested you to put ISP DNS as forwarers, that should work too)
Ofcourse it all depends on your DNS server setup…..
And the confusing part about your DNS server is external IP?????
internal ip: 192.168.0.2
external ip: ISP assigned
gtw: ISP assigned
forwarders: ISP DNS servers (it should be two of them)
you can use DNS lookup in ZS to find ISPs DNS server names an IPs so you do not have to use ANY option in forwarders.
This setup is working.