Hi Paul,This should be fixed in the December release. As a workaround, save the legend visibility for the layer to the web map instead of on the service item itself - that worked for me in the repro case I set up. To do this, open one of your existing web maps in the ArcGIS.com map viewer -> on the layers you want hidden in the legend, select show legend and then select hide legend -> save the web map. The legend visibility for the updated layers should then be reflected in the gallery application. You'll need to follow the same steps for each web map.Thanks,Chris