I am trying to update a small network to use a Windows 2019 Server Essentials for its domain controller, DNS- and DHCP server - primarily for learning things and experimenting. I have been following a number of guides (like this one or this one). The server itself is a virtual machine under ESXi 6.7 and there will be only one DC.
I have configured a static IP, have added server roles AD, DNS and DHCP, did the basic AD config steps, added a reverse lookup zone to DNS and a default IP range to DHCP. Another client on the network was able to get an IP address via DHCP.
I did follow the recommendation to name the domain as a subdomain of an actual internet domain I own (i.e. ad.domain.tld, where domain.tld is normally a web server on a provider-hosted site).
The server claims to have no internet access - which is not correct - but that seems to be a known issue. DNS also issues a warning #4013 in server manager, but that appears to be "normal" as well.
However, I have a strange problem with DNS, that I have no explanation for.
When I do an nslookup on whichever name, the result is always:
Server: localhost
Address: 127.0.0.1
Non-authoritative answer: xxxx.DOMAIN.TLD
Address: nnn.nnn.nnn.nnn
Where nnn.nnn.nnn.nnn is the IP address of my provider-hosted webserver/domain. It does not matter which name I use - this can be 'amazon.com' (-> amazon.com.DOMAIN.TLD), a local computer 'winclient' (-> winclient.DOMAIN.TLD) or even something invalid like 'x.y.z' (-> x.y.z.DOMAIN.TLD), they all resolve to the exact same IP address.
So maybe I did something stupid or not so obviously wrong, but I have no idea what. Any help would be much appreciated. Let me know what info to provide.