I need help making front channel logout work in my application that uses C# + IdentityServer4 + Angular. My client configuration in IdentityServer4:

new Client
{
    AccessTokenType = AccessTokenType.Jwt,
    RefreshTokenExpiration = TokenExpiration.Absolute,
    IdentityTokenLifetime = identityTokenLifetime,
    AuthorizationCodeLifetime = authorizationCodeLifetime ,
    AccessTokenLifetime = accessTokenLifetime ,
    UpdateAccessTokenClaimsOnRefresh = true,
    AllowOfflineAccess = true,
    ClientId = MySiteClients.Portal,
    ClientName = "Portal client",
    ClientSecrets =
    {
        new Secret(MySiteSecrets.Portal.Sha256())
    },
    AllowedGrantTypes = GrantTypes.Implicit,
    AllowAccessTokensViaBrowser = true,
    AlwaysIncludeUserClaimsInIdToken = true,
    AbsoluteRefreshTokenLifetime = coreSettings.AbsoluteRefreshTokenLifetimeInSeconds,
    RequireConsent = false,
    RequirePkce = false,
    RedirectUris =
    {
        $"https://localhost:4200/auth-callback",
        $"https://localhost:4200/silent-refresh.html",
    },
    PostLogoutRedirectUris =
    {
        $"https://localhost:4200/logout-callback",
        $"http://localhost:4200/logout-callback",
        coreSettings.MySiteIdentityServer
    },
    BackChannelLogoutUri = $"{coreSettings.MySiteIdentityServer}/api/logout-backchannel",
    BackChannelLogoutSessionRequired = true,
    FrontChannelLogoutUri = $"https://localhost:4200/frontchannel-logout",
    FrontChannelLogoutSessionRequired = true,
    AllowedCorsOrigins =
    {
        coreSettings.PortalApiService,
        coreSettings.Portal
    },
    AllowedScopes =
    {
        StandardScopes.OpenId,
        StandardScopes.Profile,
        MySiteScopes.PortalApi
    }
}

Angular Component for handling front channel logout:

@Component({
selector: 'app-frontchannel-logout',
templateUrl: './frontchannel-logoutponent.html'
})
export class FrontChannelLogoutComponent implements OnInit {
    constructor(private router: Router,
             private authService: AuthService,
                private activatedRoute: ActivatedRoute) { }

    ngOnInit() {
      debugger;
        this.activatedRoute.queryParams.subscribe(params => {
           if (params['frontchannel-logout']) {
                this.authService.logout();
         }
       });
    }
}

The problem: Even in IdentityServer4 logs, I do not see any front channel logout request. Back channel logout works fine, but it does not fully solve my problem.

My goal: I want to log out the user from all clients (browsers) simultaneously when they log out from one browser.

Currently, only all tabs within the same browser are logged out. Other browsers still retain the session because they store the token in cookies, which remain valid for 30 minutes. The session in other browsers only expires when the token is no longer valid and fails to refresh due to revocation via back channel logout.

My question: Why isn't front channel logout being triggered? Are there any alternative ways to achieve full logout across all browsers?

Any ideas or suggestions are highly appreciated! Thank you in advance.