OpenVPN client works very well on Windows 7 machines. However, its Windows 10 and Linux executables are lacking full functionality. Thus, these lines are required to workaround this handicap.
# Windows 10 and Ubuntu
dhcp-option DNS 192.168.20.1
dhcp-option DNS 220.127.116.11
dhcp-option DOMAIN kimconnect.com
# Only on ubuntu client, ad the following directives: