Windows Server 2016 DNS Setup Not Working *** URGENT ***

Hi,

I'm currently running a server with the domain name diamond.local and setting up a new server with a new forest on the same network called hg-gwl.local but for some reason i can't get the DNS on hg-gwl.local work properly as it's causing issues with creating a relationship trust between the 2 servers for migration purposes.

I have added the DNS Role in windows server 2016 with the forward Lookup Zones "hg-gwl.local" domain and also added my server ip address 192.168.18.19 as a pointer from the hg-s-13232.hg-gwl.local data. If i ping the server dns from a different workstation on the same network it shows the following:

Reply from 192.168.18.19: byes=32 time=1ms TTL=128

Reply from 192.168.18.19: byes=32 time=1ms TTL=128

Reply from 192.168.18.19: byes=32 time=1ms TTL=128

Reply from 192.168.18.19: byes=32 time=1ms TTL=128

but when i run the command nslookup hg-gwl.local it shows the following.

Server: roco-w-12479.diamond.local
Address: 192.168.18.20

*** hg-s-13232.hg-gwl.local can't find hg-gwl.local: Non-existent domain

Why is it not finding the domain info from the server domain name hg-gwl.local?

Thanks.