If I write a converter for a custom object

i.e.

class MyObjectConverter : JsonConverter
{
            private static Type dataType = typeof(MyObject);

            public override bool CanConvert(Type objectType)
            {
                return objectType == dataType;
            }

            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
            {
                var d = value as MyObject;
                
                writer.WriteRaw("{}");
            }
}

Everything is fine unless I have a collection of MyObject
If I have a collection the serialization appears as
[{} {}] // note without the comma.

I am going to look into why this is occuring, but still working my way through the code and wondering if someone else has seen this issue.