The latest update to OpenVPN keeps the server and client configs in different directories in /etc/openvpn, although NS hasn't migrated to this scheme (yet) for the RoadWarrior service.
All I did, was to put the client VPN configuration file in /etc/openvpn/clients directory and then start the service with:
systemctl start openvpn-client@<Name of openvpn config file, without .conf extension>
You can check the status with the "systemctl status" command, using the same parameter.
Perhaps post your conf file and/or the log from the start-up for someone to check.