During your VNC Connect session you can view useful information about your connection under the session information button, found in the VNC Viewer toolbar. You may be asked for this information if you contact RealVNC Support along with diagnostics and logs.
1) While connected to your server access the VNC Viewer toolbar and select the Session information icon.
2) This will open a new window in the VNC Viewer app with information about your current session. Take a screenshot of the information and include it in your reply to RealVNC Support.