I have a point layer symbolized with unique symbols based on a field. I am using 3 basic colored circles for the different options the field could be. On my online webmaps all of the points are showing up but when the web map is opened in explorer one of the point classifications will not display. It is shown in the legend but not on the map. I have tried changing the symbol/color for each of the 3 symbols but that one will not show up. If I just show location only all points show up in both places.
Did you ever find a resolution to this? I'm experiencing something similar. I have a layer containing point and polygon sublayers. The symbology is very basic. In ArcGIS Explorer the points show, but the polygons do not, despite them all being shown in the legend (and being visible in ArcGIS Online Map Viewer).