Tweak to serialisation

prs.stores/Events/Event.cs

@@ -63,13 +63,8 @@ public static class EventUtils
     private static JsonSerializerOptions SerializationSettings()
     {
         var settings = Serialization.CreateSerializerSettings();
-        settings.TypeInfoResolver = new DefaultJsonTypeInfoResolver
-        {
-            Modifiers =
-            {
-                Serialization.WritablePropertiesOnly
-            }
-        };
+        settings.TypeInfoResolver = (settings.TypeInfoResolver ?? new DefaultJsonTypeInfoResolver())
+            .WithAddedModifier(Serialization.WritablePropertiesOnly);
         return settings;
     }