Logout is not working properly - angular-oauth-oidc

I'm using the angular-oauth-oidc library to manage authentication in an angular app. I'm also using this sample as the base for my work: https://github.com/jeroenheijmans/sample-angular-oauth2-oidc-with-auth-guards

When i start the project and try to navigate to a protected page A (protected by a guard that checks if i'm authenticated, if i'm not, it calls the initLoginFlow() method), i get redirected to the authorization server's login page, after successfully logging in, i'm redirected the page A.

When i click on a button to logout, i get redirected to a page B that i specified in the logoutUrl property of the library, and all data and tokens are deleted from the localStorage. Until this stage it's working fine.

But when i try to navigate again to the protected page A, some redirections happen and i find myself logged in and already at the page A, and tokens are available again in localStorage, without having to go to the server's login page the do what i did in the first time. Why am i not redirected again to the server's login page ?

// the guard
canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
            return this.authService.isDoneLoading$.pipe(
                filter(isDone => isDone),
                switchMap(_ => this.authService.isAuthenticated$),
                tap(isAuthenticated => {
                    return isAuthenticated || this.authService.login(state.url);
                }),
            );
        }

// auth service login
public login(targetUrl?: string) {
        this.oauthService.initLoginFlow(targetUrl || this.router.url);
        // this.oauthService.initCodeFlow(targetUrl || this.router.url); // i tried this one and same result
    }

// logout method
public logout() {
        this.oauthService.logOut();
        // this.oauthService.revokeTokenAndLogout(); // i tried this one and same result
    }

Can anyone help me with this problem ? thanks.