IdentityServer4 PostLogoutRedirectUri null

I am trying to get an implicit flow working for IdentityServer4. Logging in and out is working correctly, however PostLogoutRedirectUri returns null even though it specifies the value it should be set to. I want the logout process to be redirected back to my application after the logout is complete.

I am logging out logoutId correctly and BuildLoggedOutViewModelAsync calls are logging out:

[HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Logout(LogoutInputModel model)
    {
        var vm = await _account.BuildLoggedOutViewModelAsync(model.LogoutId);
...

      

        
        
        
      

    

This method is in my AccountService.cs class, which then calls GetLogoutContextAsync of the DefaultIdentityServiceInteractionService:

public async Task<LoggedOutViewModel> BuildLoggedOutViewModelAsync(string logoutId)
    {
        // get context information (client name, post logout redirect URI and iframe for federated signout)
        var logout = await _interaction.GetLogoutContextAsync(logoutId);
...

      

        
        
        
      

    

Creates IdentityServer4.Models.LogoutRequest.

The string property SignOutIFrameUrl

is relevant "http://localhost:5000/connect/endsession/callback?sid=bf112f7785bc860fcc4351893012622e&logoutId=d6649e7f818d9709b2c0bc659696abdf"

, but nothing else seems to have been filled in the LogoutRequest.

Unfortunately, this means that the value PostLogoutRedirectUri

is null and AutomaticRedirectAfterSignOut

also null, and on page load, the LoggedOut.cshtml

file is signout-callback.js

never loaded:

@section scripts
{
    @if (Model.AutomaticRedirectAfterSignOut)
    {
        <script src="~/js/signout-redirect.js"></script>
    }
}

      

        
        
        
      

    

Here are my config settings.

Config.cs:

public static IEnumerable<Client> GetClients()
    {
        return new List<Client>
        {
            new Client
            {
                ClientId = "implicit.client",
                AllowedGrantTypes = GrantTypes.Implicit,
                AllowAccessTokensViaBrowser = true,
                AllowedScopes = 
                {
                    IdentityServerConstants.StandardScopes.OpenId,
                    IdentityServerConstants.StandardScopes.Profile,
                    "ContractManagerAPI"
                },
                RedirectUris = { "http://localhost:9000/" },
                PostLogoutRedirectUris = { "http://localhost:9000/" },
                AllowedCorsOrigins = { "http://localhost:9000" },
                RequireConsent = false,

            }                
        };
    }

      

        
        
        
      

    

app.ts (js client):

import {UserManager} from 'oidc-client';
import { inject, Factory } from 'aurelia-framework';

@inject(Factory.of(UserManager))
export class App {
  userManager: UserManager;

  constructor(userManagerFactory){
    let config = {
      authority: 'http://localhost:5000',
      client_id: 'implicit.client',
      response_type: 'id_token token',
      scope: 'openid profile ContractManagerAPI',
      redirect_uri: 'http://localhost:9000/',
      post_logout_redirect_uri: 'http://localhost:9000/'
    };

    this.userManager = userManagerFactory(config);
  }

  login(){
    this.userManager.signinRedirect();
  }

  logout(){
    this.userManager.signoutRedirect();
  }
}

      

        
        
        
      

    

Relevant parts of Startup.cs:

services.AddIdentityServer()
                .AddTemporarySigningCredential()
                .AddInMemoryApiResources(Config.GetApiResources())
                .AddInMemoryClients(Config.GetClients())
                .AddInMemoryIdentityResources(Config.GetIdentityResources())
                .AddContractManagerUserStore()
                .AddProfileService<ContractManagerProfileService>();

      

        
        
        
      

    

Any help figuring out where I am going wrong would be greatly appreciated.

Thank!