Fixed the wrong property being added to HiddenColumns.

inabox.wpf/DynamicGrid/DynamicOneToManyGrid.cs

@@ -49,7 +49,7 @@ namespace InABox.DynamicGrid
 
             property = CoreUtils.GetOneToManyProperty(typeof(TMany), typeof(TOne));
 
-            AddHiddenColumn(property.Name);
+            AddHiddenColumn(property.Name + "." + nameof(IEntityLink.ID));
             foreach (var col in LookupFactory.RequiredColumns<TMany>())
                 HiddenColumns.Add(col);