Asp.Net Core Twitch OAuth: Correlation Failed - oauth

Question

I configured Twitch authentication for my website using this tutorial: https://blog.elmah.io/cookie-authentication-with-social-providers-in-asp-net-core/
In the Twitch dev console I added the https://localhost:44348/signin-twitch url to the callback urls. I've implemented oauth for other providers before, but having troubles with Twitch.
When I try to login, I get the Twitch authorization screen, but after clicking 'Authorize' it redirects me to /signin-twitch + params which returns a Correlation Failed exception.
Exception: An error was encountered while handling the remote login.
I have a feeling it might have to do with the routing. It's setup like this because I have a frontend application with it's own routing (hence the Fallback)
Here is all relevant code.
public void ConfigureServices(IServiceCollection services)
{
...
services.AddAuthentication(options =>
{
options.DefaultSignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
options.DefaultAuthenticateScheme = CookieAuthenticationDefaults.AuthenticationScheme;
options.DefaultChallengeScheme = CookieAuthenticationDefaults.AuthenticationScheme;
})
.AddCookie(CookieAuthenticationDefaults.AuthenticationScheme, options =>
{
options.LoginPath = "/signin";
options.LogoutPath = "/signout";
})
.AddTwitch(TwitchAuthenticationDefaults.AuthenticationScheme, options =>
{
options.ClientId = "xxx";
options.ClientSecret = "xxx";
options.Scope.Add("user:read:email");
options.SaveTokens = true;
options.AccessDeniedPath = "/";
});
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
...
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
endpoints.MapFallbackToController("Index", "Home");
});
}
public class AuthenticationController : Controller
{
[HttpGet("~/signin")]
public IActionResult SignIn(string returnUrl = "")
{
return Challenge(TwitchAuthenticationDefaults.AuthenticationScheme);
}
}

Answer 1

I think that the error occurs because you're trying to access the URL which is assigned as Callback Path.
Try some variant of this:
[HttpGet("~/signin")]
public IActionResult SignIn()
{
var authProperties = _signInManager
.ConfigureExternalAuthenticationProperties("Twitch",
Url.Action("LoggingIn", "Account", null, Request.Scheme));
return Challenge(authProperties, "Twitch");
}
Source: this answer and this one.
Other stuff to check:
Multiple clients with the same Callback Path
CookiePolicyOptions
HTTPS redirect