Connect Failed: Broker unreachable

After updating MassTransit packages to the latest version (4.1.0.1426-develop) I experience problems with registering more then 26 queues. For example, code below crushes with error

[20:51:06 ERR] RabbitMQ Connect Failed: Broker unreachable: guest@localhost:5672/test

static void Main(string[] args)
{
    var builder = new ConfigurationBuilder()
            .AddJsonFile("appsettings.json", true, true);

    var configuration = builder.Build();

    Log.Logger = new LoggerConfiguration()
        .MinimumLevel.Debug()
        .WriteTo.Console()
        .ReadFrom.Configuration(configuration)
        .CreateLogger();

    Log.Information("Starting Receiver...");

    var services = new ServiceCollection();

    services.AddSingleton(context => Bus.Factory.CreateUsingRabbitMq(x =>
    {
        IRabbitMqHost host = x.Host(new Uri("rabbitmq://guest:guest@localhost:5672/test"), h => { });

        for (var i = 0; i < 27; i++)
        {
            x.ReceiveEndpoint(host, $"receiver_queue{i}", e =>
            {
                e.Consumer<TestHandler>();
            });
        }

        x.UseSerilog();
    }));

    var container = services.BuildServiceProvider();

    var busControl = container.GetRequiredService<IBusControl>();

    busControl.Start();

    Log.Information("Receiver started...");
}

So, it can't register 27 queues. However it works if I decrease the number to 26 :)

If I downgrade MT NuGet packages to the latest stable 4.0.1 version it perfectly works and I can register up to 50 queues.

Also, another observation - with 4.1.0.1426-develop versions it takes much longer to start this very tiny app. However when I test it with latest stable 4.0.1 and try to create 50 queues it starts almost immediately.

Any ideas where this limitation came from and how to avoid it?