User doesn't seem authenticated in the pipline inside`Use` in dotnetcore 2.0

I am trying to provide an ActiveUser property to Serilog.
Unfortunately I cannot seem to find the correct spot to check for the current user.

In the below code httpContext.User.Identity.IsAuthenticated is always false?

But only when logging in with the bearer token

• The bearer token login is working correctly insofar as the user is authenticated to the controller methods, and the user needs to belong to the correct roles in order to be authenticated. Though the user name is not correctly set - the claims are present, and IsAuthenticated is set to true.
• If I use the cookie login, the user is set correctly, and the claims are set correctly, and the Serilog works correctly. This is true whether using the bearer token or a cookie to call in. Once the user is logged in with a cookie it always works.

When the bearer token is validated, the user is not immediately set?

The project is aspnetcore 2.0

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{

    ... (other configuration items)

    app.UseIdentityServer();
    app.UseAuthentication();

    app.Use(async (httpContext, next) =>
    {
        // HERE IsAuthenticated IS ALWAYS FALSE
        // HERE THE CLAIMS ARE ALWAYS EMPTY, UNLESS
        // I LOGIN USING THE COOKIE AS WELL - THEN IT WORKS
        var userName = httpContext.User.Identity.IsAuthenticated 
            ? httpContext.User.GetClaim("name")
            : "(unknown)";
        LogContext.PushProperty(
            "ActiveUser",
            !string.IsNullOrWhiteSpace(userName)
                 ? userName
                 : "(unknown)");
        await next.Invoke();
    });

    app.UseMvc(
        routes =>
        {
            routes.MapRoute(
                "default",
                "{controller=Home}/{action=Index}/{id?}");
        });

In my controller method, the User is set correctly, and is authenticated.

[Authorize]
[HttpGet("user")]
public object UserDetail()
{
    // HERE THE CLAIMS ARE SET, IsAuthenticated IS ALWAYS TRUE
    // AS THE USER MUST BE AUTHENTICATED TO GET HERE
    Debug.Assert(this.User.Identity.IsAuthenticated == true)

edit
Digging into the problem further it would appear that the JWTBearer token is validated AFTER my middleware has already executed. The middleware needs to execute AFTER the token is validated.

TL;DR
(the full configuration)

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
        app.UseBrowserLink();
    }
    else
    {
        app.UseExceptionHandler("/Home/Error");
    }

    app.UseStaticFiles();
    app.UseIdentityServer();
    app.UseAuthentication();
    app.Use(async (httpContext, next) =>
                    {
                        var userName = httpContext.User.Identity.IsAuthenticated 
                        ? httpContext.User.GetClaim("email")
                        : "(unknown)";
                        LogContext.PushProperty("ActiveUser", !string.IsNullOrWhiteSpace(userName) ? userName : "(unknown)");
                        await next.Invoke();
                    });

    app.UseMvc(
        routes =>
        {
            routes.MapRoute(
                "default",
                "{controller=Home}/{action=Index}/{id?}");
        });

}

(more configuration)

   public void ConfigureServices(IServiceCollection services)
   {
        JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Clear();
        services.AddAuthentication()
            .AddOpenIdConnect(
                o =>
                {
                    o.Authority = "https://localhost:44319";
                    o.ClientId = "api";
                    o.ClientSecret = "secret";
                    o.RequireHttpsMetadata = false;
                    o.ResponseType = "code id_token token";
                    o.GetClaimsFromUserInfoEndpoint = true;
                })
            .AddJwtBearer(
                o =>
                {
                    o.Authority = "https://localhost:44319";
                    o.Audience = "api";
                    o.RequireHttpsMetadata = false;
                    //o.SaveToken = true;
                });

        services.AddMemoryCache();
        services.AddIdentity<ApplicationUser, ApplicationRole>(
                x =>
                {
                    x.Password.RequireNonAlphanumeric = false;
                    x.Password.RequireUppercase = false;
                })
            .AddEntityFrameworkStores<FormWorkxContext>()
            .AddDefaultTokenProviders()
            .AddIdentityServer();

        // NB
        services.Configure<IdentityOptions>(
            options =>
            {
                options.ClaimsIdentity.RoleClaimType = ClaimTypes.Role;
                options.ClaimsIdentity.UserNameClaimType = ClaimTypes.Name;
            });

        services.ConfigureApplicationCookie(
            options =>
            {
                options.LoginPath = "/login";
                options.LogoutPath = "/logout";
                options.Events.OnRedirectToLogin = this.ProcessStatusCodeResponse;
            });

        services.AddIdentityServer()
            .AddDeveloperSigningCredential()
            .AddInMemoryIdentityResources(Config.GetIdentityResources())
            .AddInMemoryApiResources(Config.GetApis())
            .AddInMemoryClients(Config.GetClients())
            .AddAspNetIdentity<ApplicationUser>();

        services.AddTransient<IEmailSender, EmailSender>();

        services.AddMvc(
                _ =>
                {
                    _.Filters.Add(
                        new AuthorizeFilter(
                            new AuthorizationPolicyBuilder(
                                    JwtBearerDefaults.AuthenticationScheme,
                                    IdentityConstants.ApplicationScheme)
                                .RequireAuthenticatedUser()
                                .Build()));
                    _.Filters.Add(new ExceptionFilter());
                    _.ModelBinderProviders.Insert(0, new PartyModelBinderProvider());
                    _.ModelBinderProviders.Insert(0, new DbGeographyModelBinder());
                    _.ModelMetadataDetailsProviders.Add(new KeyTypeModelMetadataProvider());
                })
            .AddFluentValidation(fv => fv.RegisterValidatorsFromAssemblyContaining<Startup>())
            .AddJsonOptions(json => json.SerializerSettings.Converters.Add(new DbGeographyJsonConverter()));
    }