Message Title

In my larger project, I am getting EntityNotFoundException for OptionalChild while saving Parent class (which has both optional & non optional OneToOne children).
I am yet not able to reproduce this on the sample project yet. The stacktrace I'm getting during save is below
Caused by: javax.persistence.EntityNotFoundException: Unable to find com.acme.domain.MyChildOneToOne with id 53
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$JpaEntityNotFoundDelegate.handleEntityNotFound(EntityManagerFactoryBuilderImpl.java:158) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:227) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:262) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.event.internal.DefaultLoadEventListener.doOnLoad(DefaultLoadEventListener.java:121) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:89) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1237) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.internal.SessionImpl.internalLoad(SessionImpl.java:1120) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.type.EntityType.resolveIdentifier(EntityType.java:646) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.type.EntityType.resolve(EntityType.java:431) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.type.EntityType.nullSafeGet(EntityType.java:262) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.initializeLazyPropertiesFromDatastore(AbstractEntityPersister.java:1091) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.initializeLazyProperty(AbstractEntityPersister.java:1002) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.bytecode.enhance.spi.interceptor.LazyAttributeLoadingInterceptor$1.doWork(LazyAttributeLoadingInterceptor.java:105) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.bytecode.enhance.spi.interceptor.Helper.performWork(Helper.java:97) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.bytecode.enhance.spi.interceptor.LazyAttributeLoadingInterceptor.loadAttribute(LazyAttributeLoadingInterceptor.java:76) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.bytecode.enhance.spi.interceptor.LazyAttributeLoadingInterceptor.fetchAttribute(LazyAttributeLoadingInterceptor.java:72) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:116) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.event.internal.DefaultMergeEventListener.cascadeOnMerge(DefaultMergeEventListener.java:461) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.event.internal.DefaultMergeEventListener.entityIsPersistent(DefaultMergeEventListener.java:202) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:176) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:69) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:881) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:867) ~[hibernate-core-5.2.10.Final.jar:5.2.10.Final]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_121]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_121]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_121]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_121]
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:298) ~[spring-orm-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at com.sun.proxy.$Proxy152.merge(Unknown Source) ~[?:?]
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:511) ~[spring-data-jpa-1.11.1.RELEASE.jar:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_121]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_121]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_121]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_121]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:504) ~[spring-data-commons-1.13.1.RELEASE.jar:?]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:489) ~[spring-data-commons-1.13.1.RELEASE.jar:?]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:461) ~[spring-data-commons-1.13.1.RELEASE.jar:?]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61) ~[spring-data-commons-1.13.1.RELEASE.jar:?]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282) ~[spring-tx-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) ~[spring-tx-4.3.7.RELEASE.jar:4.3.7.RELEASE]