ASP.NET Core Middleware doesn't redirect

I have the following custom middleware that sets the current culture info.

At the end, I want to redirect to another page, but my code isn't working.

In use, it seems like the execution stop's after invoking my middleware.

It currently uses context.Response.Redirect(redir);.

Middleware, SetCulture.cs:

public class SetCulture
{
    private readonly RequestDelegate _next;

    public SetCulture(RequestDelegate next)
    {
        _next = next;
    }

    public async Task Invoke(HttpContext context, IAssetsConfigAccessor config)
    {
        string name = string.Empty;

        if (context.Request.Query.Count > 0 && context.Request.Query.ContainsKey("culture"))
        {
            context.Session.SetString("Culture", context.Request.Query["culture"]);
            name = context.Request.Query["culture"];
        }
        else if (context.Session.Keys.Contains("Culture"))
        {
            name = context.Session.GetString("Culture");
        }
        else if (context.Request.Cookies.ContainsKey("Culture"))
        {
            name = context.Request.Cookies["Culture"];
        }
        else
        {
            ISite site = await config.GetSiteAsync();

            if (site.Cultures.Count() > 0)
            {
                ISiteCulture siteCult = site.Cultures.SingleOrDefault(c => c.IsDefault);

                if (!siteCult.Null())
                {
                    name = siteCult.Culture.Name;
                }
                else
                {
                    name = Thread.CurrentThread.CurrentCulture.Name;
                }

                context.Session.SetString(AssetsStatics.CacheCurrentCultureName, name);
            }
            else
            {
                ICulture tmp = await config.GetCultureAsync(false);
                name = tmp.Name;
            }
        }

        CultureInfo cult = new CultureInfo(name);
        CultureInfo.CurrentCulture = cult;
        CultureInfo.CurrentUICulture = cult;

        string redir = context.Request.Query.ContainsKey("returnUrl") ? context.Request.Query["returnUrl"] : "/";

        context.Response.Redirect(redir);

        await _next.Invoke(context);
    }
}

How I configure it in Program.cs:

app
    .UseWhen(cntx => cntx.Request.Path.StartsWithSegments("/Assets/SetCulture")
                     && cntx.Request.Query.ContainsKey("Culture"), 
             bld => { bld.UseMiddleware<SetCulture>(); });