MVC JSON Serializer Lifetime?

I noticed some interesting behavior with JSON serialization in which references are preserved. I'm guessing the JSON serializer is set up as a singleton, and therefore its reference resolver is never reset.

I have created the default MVC app in Visual studio, with the following modifications:

public void ConfigureServices(IServiceCollection services)
        {
            services.AddOptions();

            services.Configure<MvcJsonOptions>(options =>
            {
                options.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
            });

            // Add framework services.
            services.AddMvc();
        }

[Route("api/[controller]")]
    public class ValuesController : Controller
    {
        // GET api/values
        [HttpGet]
        public MyValue Get()
        {
            return new MyValue()
            {
                Name = "ABCD"
            };
        }

        public class MyValue
        {
            public string Name { get; set; }
        }
    }

If you hit that controller you see on the first GET:

{"$id": "1","Name": "ABCD"
}

On the second GET:

{"$id": "2","Name": "ABCD"
}

And so on, which leads me to believe it is never resetting its reference resolver. Is this expected behavior, and I am just new to JSON that contains references, or is this an issue that could potentially keep on growing the underlying dictionary that is maintained for JSON reference resolution?