Spring Security SAML2 CORS Origin no logged event after authenticated

Question

I want to set up a spring security SAML2, with angular application as frontEnd.

The front end application is hosted in different domain. This is how I configured my SpringSecurity:

protected void configure(HttpSecurity http) throws Exception {  
        
        http
            // setting up ssl 
            .requiresChannel(channel -> channel.anyRequest().requiresSecure())
            // disabling csrf here, you should enable it before using in production
            .csrf().disable()
            .cors()
            .and()
            .authorizeRequests()
            .antMatchers("/api/auth/**").permitAll()
            .anyRequest().authenticated().and()
            .sessionManagement().sessionFixation().none().and()
            .saml2Login()
            .successHandler(appAuthenticationSuccessHandler())
            .defaultSuccessUrl("http://127.0.0.1:4200", true)
            .permitAll()
            .and()
            .httpBasic()
            .and()
            .headers()
            .frameOptions()
            .disable()
            ;
                                            
        // add auto-generation of ServiceProvider Metadata
        Converter<HttpServletRequest, RelyingPartyRegistration> relyingPartyRegistrationResolver = new DefaultRelyingPartyRegistrationResolver(relyingPartyRegistrationRepository);
        Saml2MetadataFilter filter = new Saml2MetadataFilter(relyingPartyRegistrationResolver, new OpenSamlMetadataResolver());
        http.addFilterBefore(filter, Saml2WebSsoAuthenticationFilter.class);
        
    }

In my front to chekout if the user is logged or not I use this open endpoint:

https://localhost:8443:/api/auth

My front end is hosted in:

http://localhost:4200

The probleme is after logging, when I try the end point from http://localhost:4200 I get the user information. but when I try the same endpoint from http://127.0.0.1:4200, the response is that there is no user logged.

Any idea?