If you have unpublished changes but the Publish item is not available on the Site Configuration Screen, that means that the Client is not connected to the GRIDSMART ProcessorConnectivity to a site can be intermittent on very slow or spurious network connections.

The Publish button may become available when not connected if you have removable drives connected to your Client machine with which to use Publish To Drive. This features was removed in version 19.3.