We rely on GeoMind to detect geo information (country, city, ...) for usage events. Usually, when GeoMind is unable to detect the location of the usage event, the solr event will contain "Unknown Country". We have now seen cases where NO geo information is added to the usage event at all.
One pattern or case we see is when traffic originates from the same machine (127.0.0.1), for example with a curl. But we don't yet know the full extent of the problem or the solution.