BlackHoyt wrote
When the user connects to the server it gets the desired IP address. But when logs in from an another device (without disconnecting the first connection), it also receives the same IP address (configured in the file located in the /etc/openvpn/server/ccd/common_name file) and latter connection kicks out the first one. And also what I see in the server's log, that the connection is continuously bouncing between the two devices.
Which is exactly how it should be and will remain.
The problem you have is with your users behavior not with Openvpn.