Spring seems to be ignoring Hibernate5Module and lazy loading of hibernate object

Question

Exception

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class org.hibernate.proxy.pojo.bytebuddy.ByteBuddyInterceptor and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: java.util.ArrayList[0]->challenge.ChallengeAttempt["user"]->user.User$HibernateProxy$EvJuQSUg["hibernate_lazy_initializer"])

My entity has a ManyToOne relationship as follows:

    @Entity
    public class ChallengeAttempt{
    //rest of the fields and setters/getters
    //....
        @ManyToOne(fetch = FetchType.LAZY)
        @JoinColumn(name = "USER_ID")
        private User user;
    }

And this is my contorller class which fetches a list of data:

    @RestController
    public class MyController{
    @GetMapping("attempts")
        public ResponseEntity<List<ChallengeAttempt>> getStatistics(@RequestParam(name = "alias") String alias) {
            return ResponseEntity.ok(challengeService.getStatsForUser(alias));
        }
    }

Then I added a configuration to solve the lazy loading exception (fail on empty bean):

    @Configuration
    public class JsonConfiguration {
        @Bean
        public Module hibernate5Module() {
            Hibernate5Module module = new Hibernate5Module();
            return module;
        }
    }

The problem is that when I send a get request to fetch latest attempts (controller getStatistics method) I still get the exception as if JsonConfiguration didn't exist. (I have put this class under the main SptringBootApplication class, so it is actually being scanned by the Spring.)

---

UPDATE: I realized that Spring does not automatically register the Hibernate5Module into objectMapper. Using ApplicationContext I made sure that the hibernate5Module is successfully loaded. Then, when I checked the registered modules in objectMapper bean, I noticed it is empty (Meaning that no module has been registered). By registering hibernate5Module bean in objectMapper as follows I could make the Spring to work properly:

objectMapper.registerModule(hibernate5Module);

However, I think it's just a hack and is not recommended at all. So, why doesn't Spring register hibernate5Module automatically? Is this a bug in Spring?