How to make the hostname of VM resolvable when Cisco VPN is coected?

In my Windows 10 computer, I have a VirtualBox Ubuntu 16.04 LTS VM in bridge adapter network setting. I have been able to use the hostname of the VM to SSH, Samba, and browse webpages inside the VM.

Also, the Windows 10 computer has Cisco AnyCoect Secure Mobility Client installed, so that I can remotely access my company's LAN. Like, remote desktop into the office computer, accessing file server, etc.

Recently, the IT department has told us to update the VPN client. After that, I have found the computer unable to resolve the hostname of the VM when the VPN is coected. When the VPN is discoected, the hostname can be resolved again.

The updated version of the Cisco client is Version 4.2.03013. I do not know the version number before the update.

What should I do to make the hostname stays resolvable when the VPN is coected?