JPARepository - sometimes create duplicate records - jpa

Question

I have the following entity class.
#Data
#EqualsAndHashCode(callSuper=false)
#ToString(callSuper=true)
#Entity
#Table(name = "storeitem")
public class StoreItem extends SellableStoreItem {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private UUID id;
#EqualsAndHashCode.Exclude
#ToString.Exclude
#ManyToOne
#JoinColumn(name = "store_id")
private Store store;
#EqualsAndHashCode.Exclude
#ToString.Exclude
#ManyToOne
#JoinColumn(name = "storeitemcategory_id", nullable = true)
private StoreItemCategory storeItemCategory;
#EqualsAndHashCode.Exclude
#OneToMany(fetch = FetchType.EAGER, mappedBy = "storeItem")
private List<StoreItemTranslation> storeItemTranslationList = new ArrayList<>();
#EqualsAndHashCode.Exclude
#OneToMany(mappedBy = "storeItem",
cascade = CascadeType.ALL,
orphanRemoval = true)
private List<StoreItemOptionCollectionSelection> storeItemOptionCollectionSelections = new ArrayList<>();
#EqualsAndHashCode.Exclude
#Column(name = "uid")
private UUID uid = UUID.randomUUID();
#EqualsAndHashCode.Exclude
#CreationTimestamp
#Column(name = "createddate", nullable = false)
private LocalDateTime createdDate;
#EqualsAndHashCode.Exclude
#Column(name = "iscurrent", nullable = false)
private boolean isCurrent = true;
And in my service layer, I do the following.
private StoreItemResponse setStoreItemCreate(StoreItemDTO storeItemDTO, Store store, StoreItemCategory storeItemCategory) {
StoreItem storeItem = new StoreItem(storeItemDTO, store, storeItemCategory);
if(storeItemDTO.getUid() != null){
storeItem.setUid(storeItemDTO.getUid());
}
storeItem = storeItemRepository.save(storeItem);
// Create Translations for store Item
for (TranslationDTO translationDTO : storeItemDTO.getTranslationDTOs()) {
StoreItemTranslation translation = new StoreItemTranslation(translationDTO, storeItem);
storeItemTranslationRepository.save(translation);
}
return new StoreItemResponse(storeItem.getId(), DtoResponseStatus.OK);
}
However, when testing the code, I notice that there are times (not often but some cases) I see duplicate records (with different id) are being saved to database. And the duplicates are saved 2ms apart so I suspect storeItem = storeItemRepository.save(storeItem); created the duplicate records.
Why would this happen?