Such behavior may be observed although the HMI/iPC is notifying the user that the SiteManager running on the HMI/iPC is connected and registered on the remote GateManager. If the Sitemanager connection status does not indicate that it is connected and registered on the remote GateManager, setup the SiteManager connection parameters.
Otherwise, the domain token you defined is likely not taken into account by the GateManager, which occurs if your SiteManager has been registered at least once in another customer domain defined by a previous domain token that was set in the SiteManager connection parameters. In order to solve this issue, add an equal sign '=' at the beginning of the newer domain token parameter to be taken into account.