MutableLiveData containing List<> always passed by reference. Want to pass it by value

Question

I have a seperate class for my sqlite operations named DBOperations.java which fetch data and pass all data to my ViewModel named HomeActivityViewModel.java through a interface named DBOperationsListener

public interface DBOperationsListener {
    void itemDataLoaded(List<ItemData> itemDataList);
}

my HomeActivityViewModel.java

public class HomeActivityViewModel extends AndroidViewModel implements DBOperations.DBOperationsListener {

    private DBOperations dbOperations;
    private MutableLiveData<List<ItemData>> orderItemDataMLData = new MutableLiveData<>();
    private MutableLiveData<List<ItemData>> returnItemDataMLData = new MutableLiveData<>();
    
    public HomeActivityViewModel(@NonNull Application application) {
        super(application);
        this.application = application;
        dbOperations = new DBOperations(application, this);
        dbOperations.loadItemData();
    }

    public MutableLiveData<List<ItemData>> getOrderItemDataMLData() {
        return orderItemDataMLData;
    }

    public MutableLiveData<List<ItemData>> getReturnItemDataMLData() {
        return returnItemDataMLData;
    }

    @Override
    public void itemDataLoaded(List<ItemData> itemDataList) {
        orderItemDataMLData.postValue(new ArrayList<>(itemDataList));
        returnItemDataMLData.postValue(new ArrayList<>(itemDataList));
    }

on my FirstFragment

private List<ItemData> itemDataList;
homeActivityViewModel.getOrderItemDataMLData().observe(getViewLifecycleOwner(), (itemData) -> {
    itemDataList = itemData;
});

then later on the same fragment I get an item and update the values of that item as this

ItemData item = itemDataList.get(index);
item.setValue(value);

When I update that value both MutableLiveData lists (orderItemDataMLData and returnItemDataMLData) on the HomeActivityViewModel item value is set to the value that has assigned on the fragment.

What I have Tried : changed method itemDataLoaded to

@Override
public void itemDataLoaded(List<ItemData> itemDataList) {
    List<ItemData> itemDataArrayList1 = new ArrayList<>();
    itemDataArrayList1.addAll(itemDataList);
    orderItemDataMLData.postValue(itemDataArrayList1);
    List<ItemData> itemDataArrayList2 = new ArrayList<>();
    itemDataArrayList2.addAll(itemDataList);
    returnItemDataMLData.postValue(itemDataArrayList2);
}

but still both MutableLiveData is updated when the value assigned.

I cannot understand why it is happening. since I have created two new ArrayLists before assigning the value.

please follow this link to the example app which creates this problem