I make a change and restart via monitor but the change does not seem to take effect.

The OPC Server is a thin server, which means that it does not contain a user interface, but the interface is completely external and consists of a real OPC client. The changes made are loaded when the server restarts. The OPC standard says that there must be a small time delay from when you press stop until the server actually crashes. If you restart too quickly, the server will not have time to stop and no new configuration file will be loaded. As of version 1.3.0.1, the server status is displayed in the status bar at the bottom right. This means that it will be easier to understand when the server has really stopped.