I have implemented ADFS login in both CMS and manager startup.cs method (this is shortened for simplicity)

public void Configuration(IAppBuilder app)
        {
            using (var applicationOptions = new ApplicationOptions
            {
                ConnectionStringName = _connectionStringHandler.Commerce.Name
            })
            {
                app.AddCmsAspNetIdentity(applicationOptions);
            }


            app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);

            

            app.UseCookieAuthentication(new CookieAuthenticationOptions());

            
            app.UseOpenIdConnectAuthentication(new OpenIdConnectAuthenticationOptions
            {
                // client specific code here
                 ........

            app.UseStageMarker(PipelineStage.Authenticate);


            app.Map(url, map => map.Run(ctx =>
            {
                if (ctx.Authentication.User?.Identity == null || !ctx.Authentication.User.Identity.IsAuthenticated)
                {
                    ctx.Authentication.Challenge(OpenIdConnectAuthenticationDefaults.AuthenticationType);
                    return Task.Delay(0);
                }

                var redirectTo = new Uri(postLoginRedirectUri).AbsoluteUri;

                return Task.Run(() => ctx.Response.Redirect(redirectTo));
            }));

            app.Map(logoutUrl, map =>
            {
                map.Run(ctx =>
                {
                    ctx.Authentication.SignOut(CookieAuthenticationDefaults.AuthenticationType);

                    return Task.Run(() => ctx.Response.Redirect(new Uri(postLogoutRedirectUri).AbsoluteUri));
                });
            });

            AntiForgeryConfig.UniqueClaimTypeIdentifier = ClaimTypes.NameIdentifier;



        }

Logging into CMS part ensures that user is logged into manager part as well.

Logging out from the manager part using the top left Sign out link results in error with the following message:

"OpenIdConnectMessage.Error was not null, indicating an error. Error: 'server_error'. Error_Description (may be empty): 'MSIS9604%3a+An+error+occurred.+The+authorization+server+was+not+able+to+fulfill+the+request.'. Error_Uri (may be empty): ''."

I have put /Apps/Shell/Pages/Logout.aspx as logout endpoint but I see now that it is just a resulting page after logging out. Sign out link has # as a value for href attribute.

I couldn't figure out what URL should be provided to the IT team that is responsible for setting up the ADFS to function properly.