Click on clustered point on max zoomed layer

There are a lot of closely spaced points on my map. Sometimes they are so close, that remain clustered on maximum zoom level. So nothing happens when I click on it.

I think it would be better, if then we will zoom to max level, we will be able to see all clustered points (for example as list) in popup. For doing this I rewrite file geocluster.leaflet.bbox.js in my custom module and change clickOnClustered function:

clickOnClustered: function(e, featureData, layer) {
        var map = layer._map;
		
		// Close any other opened popup.
        if (map._popup) {
          map._popup._source.closePopup();
        }
		
		if (map._zoom == map._layersMaxZoom && featureData.cluster_items > 1) {		
			map.setView(layer.getLatLng(), map._zoom);
			var popupText = featureData.properties.name;			
			layer.bindPopup(popupText);
		}
		else {	
			map.setView(layer.getLatLng(), map._zoom + 1);
		}
    }

But featureData.properties.name varible contains only name for one item (but there are 2 clustered items).

What is the source of the problem? Is this problem comes with Group Concat arregation function?