I am using the platform Ushahidi Web-2.7.3 , see: http://ti5.net.br/provedorlegal.com.br, and when I zoom in beyond a certain level, the clustered markers disappear from the map. I also tested this on an older version of a site, see: http://movimentofichalimpa.org/mapa, where the clustered markers do not disappear on zooming in, but just become ungrouped, as is normal with a cluster strategy. How can I make the markers remain on the map when zooming in?