Umbraco + OpenId + Thinktecture Puzzle

Question

I have been trying to figure this out for 2 days now and have decided it time to ask for help. Here is the setup:

Running Umbraco 7.5.6 with the following packages:

• UmbracoIdentity 5.0.0
• UmbracoCms.IdentityExtensions 1.0.0
• UmbracoCms.IdentityExtesnions.AzureActiveDirectory 1.0.0

We are also running a Thinktecture SSO Server

• IdentityServer3

Here are the requirements:

• Back Office Users must log in via AAD or Internal Users (this is done and working)
• Members must log in via the Thinktecture SSO Server
  • If the member is not on the home page, they must be redirected back to whatever page they were attempting to access after successful login

This all seems straight forward so here is the code I have so far. This is the Middleware I wrote to stick into the Owin Startup Process:

public static IAppBuilder ConfigureFrontEndSsoAuth(this IAppBuilder app)
{
    //var postLoginRedirectUrl = "";
    var ssoOptions = new OpenIdConnectAuthenticationOptions
    {
        SignInAsAuthenticationType = CookieAuthenticationDefaults.AuthenticationType,
        Authority = Config.SsoAuthority,
        ClientId = Config.SsoClientId,
        CallbackPath = new PathString("/umbraco/surface/UmbracoIdentityAccount/ExternalLoginCallback"),
        RedirectUri = "http://bacp.dev/umbraco/surface/UmbracoIdentityAccount/ExternalLoginCallback",
        ResponseType = Config.SsoResponseType,
        Scope = Config.SsoScope,
        AuthenticationMode = AuthenticationMode.Passive,
        Notifications = new OpenIdConnectAuthenticationNotifications()
        {
            SecurityTokenValidated = async x =>
            {
                // Will deal with Claims soon
            }
        }
    };

    ssoOptions.Caption = "Member SSO";
    ssoOptions.AuthenticationType = String.Format(CultureInfo.InvariantCulture, Config.SsoAuthority);
    ssoOptions.SetExternalSignInAutoLinkOptions(new ExternalSignInAutoLinkOptions(autoLinkExternalAccount: true));
    app.UseOpenIdConnectAuthentication(ssoOptions);
    return app;
}

Here are my two controller methods:

[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public ActionResult ExternalLogin(string provider, string returnUrl = null)
{
    if (returnUrl.IsNullOrWhiteSpace())
    {
        returnUrl = Request.RawUrl;
    }

    // Request a redirect to the external login provider
    return new ChallengeResult(provider,
        Url.SurfaceAction<UmbracoIdentityAccountController>("ExternalLoginCallback", new { ReturnUrl = returnUrl }));
}

[HttpGet]
[HttpPost]
[AllowAnonymous]
public async Task<ActionResult> ExternalLoginCallback(string returnUrl = null)
{
    if (String.IsNullOrEmpty(returnUrl))
    {
        returnUrl = "/";
    }
    var loginInfo = await OwinContext.Authentication.GetExternalLoginInfoAsync();
    if (loginInfo == null)
    {
        //go home, invalid callback
        return RedirectToLocal(returnUrl);
    }

    // Sign in the user with this external login provider if the user already has a login
    var user = await UserManager.FindAsync(loginInfo.Login);
    if (user != null)
    {
        await SignInAsync(user, isPersistent: false);
        return RedirectToLocal(returnUrl);
    }
    else
    {
        // If the user does not have an account, then prompt the user to create an account
        ViewBag.ReturnUrl = returnUrl;
        ViewBag.LoginProvider = loginInfo.Login.LoginProvider;

        return View("ExternalLoginConfirmation", new ExternalLoginConfirmationViewModel { Email = loginInfo.Email });
    }
}

And last, the login action on the view:

<form action="/Umbraco/surface/UmbracoIdentityAccount/ExternalLogin" method="post">
    @Html.AntiForgeryToken()
    <input type="hidden" name="provider" value="@Config.SsoAuthority"/>
    <input type="hidden" name="returnUrl" value="@Request.RawUrl"/>
    <input type="submit" class="profile-summary__link" value="Login"/>
</form>

Now, this is where I get lost and I am either just missing something really small or something. The following steps are the issue at hand:

1. The Umbraco Page Loads up
2. I am able to click on "Login" which redirects to the SSO Server
3. If I am not logged in, I login | If I am logged in, it validated my cookie and sends me back
4. It claims it's sending me to ExternalLoginCallback but if I put a breakpoint on the controller method it never hits hit.
5. It then tries to redirect back to ExternalLogin (not sure where it's getting this from)

Any help or suggestions would be great.