Model is still null due to Json serialization issue with converting number to string in asp.net with net6

Question

I have an API app with .net6, with following configuration :

builder.Services.AddControllers()
    .AddJsonOptions(options =>
    {
        options.JsonSerializerOptions.PropertyNamingPolicy = null;
        options.JsonSerializerOptions.PropertyNameCaseInsensitive = true;
        options.JsonSerializerOptions.NumberHandling = JsonNumberHandling.AllowReadingFromString;
        ...
    });

Also tried this :

builder.Services.AddControllers();

builder.Services.Configure<JsonOptions>(options =>
{
StringEnumConverter(allowIntegerValues: true));
    options.JsonSerializerOptions.NumberHandling =JsonNumberHandling.AllowReadingFromString;
    options.JsonSerializerOptions.PropertyNamingPolicy = null;
    options.JsonSerializerOptions.PropertyNameCaseInsensitive = true;
    options.JsonSerializerOptions.Converters.Add(new Json
});

How ever when a model which has a string property, passed by post to an action, but that property set with number, the model is always null :

Request:

{ "AA": 3, }

Mode:

public class SampleModel { public string AA { get; set; } }

However if I use this convertor and clean the 'NumberHandling' from configuration, it works.

Is there any configuration I am missing ?