Updating Map Icons

I have a problem where the following is not updating all items on the map. Is there a place where Items need to be registered for this call? I’ve verified that the proper icon is being assigned, but only certain groups of items are updating on the map.

item.MapIconKey = mapIconKey;

EventServerControl.Instance.ItemStatusChanged( item );

Are you using the methods that the Sensor Monitor sample does? The sample might hold the answer.

https://doc.developer.milestonesys.com/html/index.html?base=samples/sensormonitor_sample.html&tree=tree_search.html?search=sensor+monitor