Why spring data redis findById returns null values in Optional after upgrading to version 2.3.2.RELEASE

spring repository findById() is working fine on spring-data-redis version 2.3.1.RELEASE

its failed on spring-data-redis version 2.3.2.RELEASE

Here is link to sample repository, edit version in pom.xml file, then run, then see the issue

https://github.com/mnguyencntt/spring-data-redis-optional

My logic code is very simple:

if studentId found, return existing RedisStudent object.

else create new RedisStudent & store in Redis, return new RedisStudent object.

RedisInfoController.java

    final Optional<RedisStudent> redisExisting = redisStudentRepository.findById(studentId);
    if (redisExisting.isPresent()) {
      // Spring boot 2.3.2 will print out: RedisStudent(id=null, name=null, age=null, creationTime=null)
      // Spring boot 2.3.1 will print out: RedisStudent(id=12345, name=Minh, age=28, creationTime=2020-07-28T21:31:18.318)
      log.info("{}", redisExisting.get());
      return redisExisting.get();
    }
    // Spring boot 2.3.1 will print out: Optional.empty
    log.info("{}", redisExisting);
    RedisStudent student = new RedisStudent();
    student.setId(studentId);
    student.setName("Minh");
    student.setAge("28");
    student.setCreationTime(LocalDateTime.now());
    return redisStudentRepository.save(student);