You cannot query the internal DNS server because the external one is used.
This is by design when you have registered the domain internal and external.
You use the DNS MMC (=microsoft management console) Than you click on the DNS Server and choose properties. Under forwarders you add a new DNS-Domain. In the list of forwarders you type the IP address of the internal DNS server.
Please note that the internal DNS server is used to resolve all the queries. You cannot use external resolution. This is by design when the DNS domain is registered internal and external.
About the Author
Wim Peeters is electronics engineer with an additional master in IT and over 30 years of experience, including time spent in support, development, consulting, training and database administration. Wim has worked with SQL Server since version 6.5. He has developed in C/C++, Java and C# on Windows and Linux. He writes knowledge base articles to solve IT problems and publishes them on the Lubby Knowledge Platform.