Configure per request / nested container StructureMap using asp.net core

I am trying to scope my services per on a per request basis, but my injected services always seem to be scoped to the parent/root container, and subsequent requests see the state from a previous request.

I've setup a custom StructureMap container in my startup class

// Wireup the container
Container = new Container();
Container.Configure(config =>
{
    // register the dotnet framework registered services into our container
    config.Populate(services);

    // Import all the registries
    config.Scan(scanner =>
    {
        scanner.TheCallingAssembly();
        scanner.LookForRegistries();
    });
});

return Container.GetInstance<IServiceProvider>();

Register a service in a register as;

For<ITest>().Use<Test>().ContainerScoped();

Then wiredup the following middleware

var container = serviceProvider.GetRequiredService(typeof(IContainer)) as IContainer;
if (container != null)
{
    using (var requestContainer = container.GetNestedContainer())
    {
        context.RequestServices = requestContainer.GetInstance<IServiceProvider>();
        await _next.Invoke(context);
    }
}
else
{
    await _next.Invoke(context);
}

Any pointers as to what I am missing? Thanks

There's no need to wire up the RequestServices property yourself. The ASP.NET host already does that for you. Just resolve what you need from the existing RequestServices provider.