cluster includes sites several blocks away
when zoomed in fairly close to the default map, there was a cluster with 19 sites in the East Village - click to see the sites, and the popup shows just 5 of the sites (top and bottom site duplicated) and the zoom in button does move the same list closer.
then I deleted one of the sites that has closed and got this message on this page: https://new.opengreenmap.org/browse/sites/5ca8b71eef1f7e01000827e7
Back to default - the 19 cluster is gone, and the deleted site is missing, good!