After each of the following steps, check to see if the Geo-Filter is displaying anything. These instructions assume that you are on the latest version.
Please make sure you have set the Geo-Filter up correctly by following the instructions here.
Make sure you are using Google Chrome as your web browser to access the NETDUMA interface.
Make sure that the Geo-Filter is enabled and that 'Show Hosts' is ticked.
Confirm that the correct device is selected on the Geo-Filter. If you've switched to using a different console, from wired to wireless or from wireless to wired then the console will show up as a new device and you will need to add the new device to the Geo-Filter.
This is because the network interfaces of the console have different identifiers (MAC Addresses) so show up as different devices on the NETDUMA.
Go to Settings > Miscellaneous, ensure you have auto cloud and bleeding edge cloud ticked and applied. If these are ticked already press apply again to re-flush the cloud.
Reboot the NETDUMA. You can do this by going to Settings > Miscellaneous and clicking 'Reboot Router'.
If none of the above works, then please make a new thread/reply to a thread you've already made regarding this and explain that you have done everything in this guide.