connect Windows10 to Active Directory

I have Windows Server 2016 on a cloud server, and want to use as AD DS.

After installing AD DS / dns on the server, joined server domain but there is a problem connecting to corporate PC(Windows 10 pro).

nslookup&host command could get IP for domain.
However, I couldn't connect Windows server.

Is it a problem that trying to connect to another network band using Public IP?
If so, is there any way to connect it?

====== error message. (it is not exact, translated) ======

The following domain controllers were verified in the query:

{server name}.{test domain}              <---- just 'test.com' also couldn't works.


But, the connection to the domain controller failed.

Common causes of this error are:

- Host (A) or [AAAA] record mapping the name of the domain controller to an IP address does not exist or has an invalid address.

- Domain controllers registered in DNS are not connected to the network or are not running.