I can not get the default validation message

I have a controller

@PutMapping(value = "/changeEmail", consumes = MediaType.APPLICATION_JSON_VALUE)
public HttpEntity<ChangeEmailDTO> showChangeEMail(
        @RequestBody @Valid ChangeEmailDTO changeEmailDTO
) {
    System.out.println("Email: " + changeEmailDTO.getEmail());

    return ResponseEntity.ok(changeEmailDTO);

If the user has given bad data then throws a MethodArgumentNotValidException exception.
I created an exception handler

public ValidationErrorDTO processValidationError(MethodArgumentNotValidException ex) {
    BindingResult result = ex.getBindingResult();
    List<FieldError> fieldErrors = result.getFieldErrors();

    return processFieldErrors(fieldErrors);

private ValidationErrorDTO processFieldErrors(List<FieldError> fieldErrors) {
    ValidationErrorDTO dto = new ValidationErrorDTO();

    for (FieldError fieldError: fieldErrors) {
        String localizedErrorMessage = resolveLocalizedErrorMessage(fieldError);
        dto.addFieldError(fieldError.getField(), localizedErrorMessage);

    return dto;

private String resolveLocalizedErrorMessage(FieldError fieldError) {
    Locale currentLocale =  LocaleContextHolder.getLocale();
    String localizedErrorMessage = messageSource.getMessage(fieldError, currentLocale);

    //If the message was not found, return the most accurate field error code instead.
    //You can remove this check if you prefer to get the default error message.
    if (localizedErrorMessage.equals(fieldError.getDefaultMessage())) {
        String[] fieldErrorCodes = fieldError.getCodes();
        localizedErrorMessage = fieldErrorCodes[0];

    return localizedErrorMessage;

One of the fields has validation created by me

@Constraint(validatedBy = EmailValidator.class)
@Target( {ElementType.FIELD} )
public @interface IsValidEmail {

    String message() default "Please enter a valid e-mail address.";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

And replace the default message in the properties file

IsValidEmail.changeEmailDTO.email=Please enter a valid e-mail address.

However, in the json data in the response is