UPDATE:
It is definitely not a bug in RC1. The cookie settings are working with the default UserManager and UserStore, so it must be something related to my UserManager/UserStore, I've overseen. I basically use the implementation here: https://github.com/jesblit/ASPNET5-FormAuthenticationLDAP
Original Post:
I have a problem with persistent logins. No matter how I configure the cookie, after 30 minutes, the User is automatically logged out (no matter how much the user interacts with the App).
I setup my App with:
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddCaching();
        services.AddSession(options => {
            options.IdleTimeout = TimeSpan.FromDays(1);
            options.CookieName = ".MySessionCookieName";
        });
        services.AddEntityFramework()
            .AddNpgsql()
            .AddDbContext<Model1>(options =>
                options.UseNpgsql(Configuration["Data:DefaultConnection:ConnectionString"]));
        services.AddIdentity<MinervaUser, MinervaRole>(options => {
            options.Cookies.ApplicationCookie.ExpireTimeSpan = TimeSpan.FromDays(1);
            options.Cookies.ApplicationCookie.SlidingExpiration = true;
            options.Cookies.ApplicationCookie.AutomaticAuthenticate = true;
        })
            .AddUserStore<MinervaUserStore<MinervaUser>>()
            .AddRoleStore<MinervaRoleStore<MinervaRole>>()
            .AddUserManager<MinervaUserManager>();
        services.AddMvc();
    }
And:
    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
    {
        loggerFactory.AddConsole(Configuration.GetSection("Logging"));
        loggerFactory.AddDebug();
        if (env.IsDevelopment())
        {
            app.UseBrowserLink();
            app.UseDeveloperExceptionPage();
            app.UseDatabaseErrorPage();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
            try
            {
                using (var serviceScope = app.ApplicationServices.GetRequiredService<IServiceScopeFactory>()
                    .CreateScope())
                {
                }
            }
            catch { }
        }
        app.UseIISPlatformHandler(options => { options.AuthenticationDescriptions.Clear(); options.AutomaticAuthentication = true; });
        app.UseSession();
        app.UseIdentity();
        app.UseStaticFiles();
        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });
    }
The Login Action is:
    [HttpPost]
    [AllowAnonymous]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Login(LoginViewModel model, string returnUrl = null)
    {
        ViewData["ReturnUrl"] = returnUrl;
        if (ModelState.IsValid)
        {
            var result = await _signInManager.PasswordSignInAsync(model.Email, model.Password, model.RememberMe, lockoutOnFailure: false);
            if (result.Succeeded)
            {
                _logger.LogInformation(1, "User logged in.");
                return RedirectToLocal(returnUrl);
            }
...
I am using the default SignInManager. As said, the Expiration Timeouts I set in Startup.Configure and Startup.ConfigureServices have no effect at all. Login -> 30mins -> automatically logged out :(
What to do to extend this time period?
(btw: the custom User, UserManager, UserStore don't interfere with teh Cookie in any way, they "just" validate the credentials (what they're supposed to ;) ))
 
    