Postman sending null values to spring login

I am having a problem which is that postman is sending null values to my login.
When I try it in browser, everything seems fine, yet when I try it out on the postman desktop app, I get a variety of things
Either 401, 200, or 301. 401 directly doesn't send any data, as if my postman post didn't exist. 200 and 301 it sends data, but null values (which I don't know how to fix)
I tried changing the login to basic spring login, using the deprecated WebSecurityConfigurerAdapter, reading stack overflow posts (most of the people with the same problem as me had some sort of typo in the code that was making them blow up), also securityFilterChain according to SpringDocs, etc.

I am currently using a custom auth to fetch the info from my DB (although I think it is not necessary at all, since I proved without this class and it worked fine)

So anyways, first of all here's the postman request I am using to try to login

Also, this too, because I had to try to see if it worked although it's the same

And here's the code related to the security

Here is my UserDetailsService class:

@Override
public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
   UserDTO user = this.getUserByUsername(username);
    return  MHelpers.modelMapper().map(user,UserPrincipal.class);
}

LoginConfiguration ( I know WebSecurityConfigurer is deprecated, I was just testing things out, with securityFilterChain the result doesn't change. In fact if I comment out this LoginConfig class, I get 401 Unauthorized and don't know how to fix it.)

@Configuration
public class LoginConfiguration extends WebSecurityConfigurerAdapter {

    @Autowired
    CustomAuthProvider authProvider;

    @Override
    protected void configure(AuthenticationManagerBuilder auth) {
        auth.authenticationProvider(authProvider);
    }

    @Override
    public void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests().anyRequest().authenticated()
                .and().httpBasic().and().formLogin().permitAll().and().csrf().disable().cors().disable();
    }

UserPrincipal.class

@Data
public class UserPrincipal implements Serializable, UserDetails{
    int id;
    private String username;
    private String password;
    private Date accountCreationDate = new Date(); 


    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return null;
    }

    @Override
    public boolean isAccountNonExpired() {
        return true;
    }

    @Override
    public boolean isAccountNonLocked() {
        return true;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return true;
    }

    @Override
    public boolean isEnabled() {
        return true;
    }

}

I can't seem to find the mistake, I would like some insight or help if somebody had this issue and knows how to solve it or maybe tell spring boot to authorize postman if it's being blocked by the security.
It's a basic username and password auth.

I also tried this:

@Override
public void configure(HttpSecurity http) throws Exception {
    http
            .csrf().disable()
            .authorizeRequests()
            .antMatchers( "/login").permitAll()
            .anyRequest()
            .authenticated()
            .and()
            .formLogin()
            .permitAll();

}

but it returned 302 (when I have automatic redirect enable, probably because postman cannot redirect to HAL explorer). My idea is for spring to handle the security and then later using react and axios do a fetch api with the username and password and bring/post the data I need.

The stack trace:

backend.Exceptions.NotFoundException: User not found
    at backend.services.UserServiceImpl.getUserByUsername(UserServiceImpl.java:115) ~[classes/:na]
    at backend.services.UserServiceImpl.loadUserByUsername(UserServiceImpl.java:160) ~[classes/:na]
    at backend.services.UserServiceImpl$$FastClassBySpringCGLIB$$831e0214.invoke(<generated>) ~[classes/:na]
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.3.23.jar:5.3.23]
    at org.springframework.aop.framework.CglibAopProxy.invokeMethod(CglibAopProxy.java:386) ~[spring-aop-5.3.23.jar:5.3.23]
    at org.springframework.aop.framework.CglibAopProxy.access$000(CglibAopProxy.java:85) ~[spring-aop-5.3.23.jar:5.3.23]
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:704) ~[spring-aop-5.3.23.jar:5.3.23]
    at backend.services.UserServiceImpl$$EnhancerBySpringCGLIB$$9a4b6ede.loadUserByUsername(<generated>) ~[classes/:na]
    at backend.services.CustomAuthProvider.authenticate(CustomAuthProvider.java:30) ~[classes/:na]
    at org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:182) ~[spring-security-core-5.7.4.jar:5.7.4]
    at org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:201) ~[spring-security-core-5.7.4.jar:5.7.4]
    at org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter.attemptAuthentication(UsernamePasswordAuthenticationFilter.java:85) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:227) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:217) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:103) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:89) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:90) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:75) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.23.jar:5.3.23]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:112) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:82) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:55) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.23.jar:5.3.23]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.session.DisableEncodeUrlFilter.doFilterInternal(DisableEncodeUrlFilter.java:42) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.23.jar:5.3.23]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:221) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:186) ~[spring-security-web-5.7.3.jar:5.7.3]
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:354) ~[spring-web-5.3.23.jar:5.3.23]
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:267) ~[spring-web-5.3.23.jar:5.3.23]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.23.jar:5.3.23]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.23.jar:5.3.23]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.23.jar:5.3.23]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.23.jar:5.3.23]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.23.jar:5.3.23]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.23.jar:5.3.23]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1789) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
    at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]

I know the problem is in this method, probably, because it is receiving a null value. The problem is that postman is sending those null values because on browser the auth works fine

public UserDTO getUserByUsername(String username) {
            User user = userRepository.findByUsername(username);
            if(user == null) {
                throw new NotFoundException("User not found");
            }
            return convertToUserDTO(user);
        }

Edit 1: This may sound stupid but I don't have a login controller because as far as I understand, spring handles it? Somebody correct me if I am wrong, but if it's not that spring's default controller is failing then I don't know what is causing the issue of the values being sent with null

Edit 2: It works with url-encoded, however I want basic auth AND form login, and the problem comes when I try to log in via json / basic auth. There, the null values start appearing.

Solution

Since no reply was given, I'll leave the code that worked for me to put basic auth as well as form login. Any other order or solution proved to be not working. This solves the 'null values' of the postman basic auth, although I cannot pass the values as a JSON (because those get passed as null)

  @Bean
    protected SecurityFilterChain configure(HttpSecurity http) throws Exception {
        http.authorizeRequests().antMatchers("/login").permitAll().anyRequest().authenticated().and().
                csrf().disable().httpBasic().and().formLogin().permitAll().and().
                cors().
                configurationSource(request -> new CorsConfiguration().applyPermitDefaultValues()); 
        return http.build();
    }