Assuming you have a config file called /etc/openvpn/server/myconfig, can you try:
systemctl start openvpn-server@myconfig
That should trigger the openvpn-server@ service file, which will replace %i in the Exec line below with what's after @ in the systemctl start command:
ExecStart=/usr/sbin/openvpn --status %t/openvpn-server/status-%i.log --status-version 2 --suppress-timestamps --config %i.conf
Assuming you have a config file called /etc/openvpn/ server/ myconfig, can you try:
systemctl start openvpn- server@ myconfig
That should trigger the openvpn-server@ service file, which will replace %i in the Exec line below with what's after @ in the systemctl start command: /usr/sbin/ openvpn --status %t/openvpn- server/ status- %i.log --status-version 2 --suppress- timestamps --config %i.conf
ExecStart=
So it should work?