Windows Defender Firewall works to protect the Operating System and user data on the computer from improper or unapproved access, use, and possible infection. The software permits or denies programs on a computer from accessing network or internet resources.
Generally, the shared drives pass as SMB(Server Message block) traffic which is a network file sharing protocol. It requires protection from attacks in which a Windows computer might be tricked into contacting a malicious server that's running inside a trusted network or to a remote server outside the network perimeter.
So after get connected to the NetExtender, the Windows Defender on the office PC might consider the remote machine as untrusted so sometimes the SMB ports will be blocked on the Windows Defender.





