Hello Roberto,
Make sure that the Append primary and connection specific DNS suffixes option is enabled in the Advanced TCP/IP Settings window of your network adapter. This option specifies that resolution for unqualified names that are used on your computer is limited to the domain suffixes of the primary suffix and all connection-specific suffixes. For more information, you may refer to the following link: Configure a Connection-Specific DNS Name. (Note: These steps are also applicable for Windows 10 machines.)
You might also be experiencing this issue because of DNS Devolution. This is applicable to computers that are in an Active Directory environment. For more information, you may refer to the following link: DNS Devolution.
For more advanced troubleshooting, we recommend that you also post this concern in the Windows 10 IT Pro section of the Microsoft TechNet forums. TechNet Forums is a community for IT professionals and advanced users.
If you need further assistance, please do not hesitate to post a reply.
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