XyDataSeries Metadata is changing when zooming or moving

Hallo,

I have a problem with drawing of 2d data in a map. The metadata for the respective points change when you zoom in or move the map.

LandmarkCollection landMarks = new LandmarkCollection();
            NAVLandmarkCollection landmarkCollection = NAVLandmarkCollection.Deserialize(@"C:\Users\Serva_admin\Documents\AGV-Viso\VS_Projekte\AGV-Viso-2\AGV-Viso-2\16-02-06-18-23-ING.lmf");
            for (int i = 0; i < landmarkCollection.Count; i++)
            {
                NAVLandmark lm = landmarkCollection.get(i);
                landMarks.Landmarks.Append(lm.X, lm.Y, new Serva.Base.Navigation.Client.NavigationPlugin.MetaData.LandmarkName("G-" + i, lm.X, lm.Y));
            }

            communicationBus.Publish(landMarks);

This function is called once and the data does not change anymore.

I uploaded the pictures of my problem in the attachment.
You can see the Name of the Point in the top-left corner changed.

I hope you can me help.