Object automatically being set to null in reflection java

I have written a reflection function which merges two objects on some pre-specified conditions :

While iterating on the fields of the object,the value of object A is correct as observed but as soon as the fields of the current object are exhausted and the function starts iterating on the next object, the fields to which values had been set ,they become NULL.

Here, I provide my reflection code and the main function :

public static void mergeObjectAndSet(Object objectA,Object objectB,Set<String> deleteSetA,Set<String> deleteSetB,Set<String> deleteSetC,String path) throws Exception {
    LOGGER.info("In merge Sets and Diff function : ");
    LOGGER.info("Deleted sets A are : "+deleteSetA+" B : "+deleteSetB+" C : "+deleteSetC);
    LOGGER.info("Object A is : "+objectA+" object B is : "+objectB);
    if(null == deleteSetA){
        deleteSetA = new HashSet<>();
    }
    else if(null == deleteSetB){
        deleteSetB = new HashSet<>();
    }

    Class classA = objectA.getClass();
    Class classB = objectB.getClass();

    LOGGER.info("Classes are : "+classA+" class B : "+classB);
    Field objectBFields[] = classB.getDeclaredFields();
    System.out.println(objectA);
    for (Field fieldB : objectBFields) {
        LOGGER.info("fields to be looped in mergeObjectAndSet are : "+objectBFields.toString() +" path is : "+path);
        fieldB.setAccessible(true);
        Class typeB = fieldB.getType();
        Object fieldAObject = fieldB.get(objectA);
        Object fieldBObject = fieldB.get(objectB);

        if (!Collection.class.isAssignableFrom(typeB)) {
            LOGGER.info("passes null check for field objects : ");
            if (isTypePrimitive(typeB)) {
                if(null != fieldAObject || null != fieldBObject) {
                    Field fieldA = classA.getDeclaredField(fieldB.getName());
                    fieldA.setAccessible(true);
                    LOGGER.info("field A is : " + fieldA.getName());
                    if (!(deleteSetA.contains(path + Constants.HYPHEN + fieldA.getName())) && (deleteSetB.contains(path + Constants.HYPHEN + fieldA.getName()))) {
                        LOGGER.info("In only deleted set case : Adding field : " + fieldA.getName() + " to deleted set");
                        deleteSetC.add(path + Constants.HYPHEN + fieldA.getName());
                        LOGGER.info("Merged object for the field : " + fieldB.getName() + " to object : " + fieldBObject + " in object : " + objectA);
                    }else if(deleteSetA.contains(path + Constants.HYPHEN + fieldA.getName()) &&  !(deleteSetB.contains(path + Constants.HYPHEN + fieldA.getName())) && null != fieldBObject && null==fieldAObject) {
                        LOGGER.info("in merge set and objects case : ");
                        fieldA.set(objectA, fieldBObject);
                        LOGGER.info("Merged object for the field for case refresh : " + fieldB.getName() + " to object : " + fieldBObject + " in object : " + objectA);
                    }else if(!(deleteSetA.contains(path + Constants.HYPHEN + fieldA.getName())) &&  !(deleteSetB.contains(path + Constants.HYPHEN + fieldA.getName()))){
                        LOGGER.info("In merge case irrespective of deleted sets : ");
                        fieldA.set(objectA, fieldBObject);
                    }
                }
            } else {
                if ((null==fieldAObject && null==fieldBObject)){
                    LOGGER.info("In both fields are null case : ");
                    LOGGER.info("Field here is : "+fieldB.getName());
                    for(String del : deleteSetA){
                        if(del.startsWith(fieldB.getName())){
                            deleteSetC.addAll(deleteSetA);
                        }
                    }
                    continue;
                }
                LOGGER.info("In non primitive type check : path here for np is : "+path);
                LOGGER.info("field name here : "+fieldB.getName());
                LOGGER.info("path here : "+path);
                LOGGER.info("object name here : "+objectA.getClass().getName());
                Field fieldA = classA.getDeclaredField(fieldB.getName());
                fieldA.setAccessible(true);
                if (null == fieldAObject) {
                    LOGGER.info("if A is null case : initialise it with an instance");
                    Constructor[] constructors = fieldA.getType().getDeclaredConstructors();

                    for (Constructor constructor : constructors) {
                        constructor.setAccessible(true);
                        if (0 == constructor.getParameterCount()) {
                            fieldAObject = constructor.newInstance();
                            break;
                        }
                    }
                }

                LOGGER.info("No test cases met, path is : "+path);

                if (null == path) {
                    LOGGER.info("when path is null new path here is : "+path);
                    mergeObjectAndSet(fieldAObject, fieldBObject, deleteSetA, deleteSetB, deleteSetC, fieldA.getName());

                } else {
                    LOGGER.info("path here when some path is there is : "+path);
                    mergeObjectAndSet(fieldAObject, fieldBObject, deleteSetA, deleteSetB, deleteSetC, path + Constants.HYPHEN + fieldA.getName());
                }
            }
        }
    }
}

The main function is :

public static void main(String args[]) {
    LeadDetailSRO leadDetailSRO1 = new LeadDetailSRO();
    LeadDetailSRO leadDetailSRO2 = new LeadDetailSRO();
    BankDetailSRO bankDetails = new BankDetailSRO();
    bankDetails.setBeneficiaryName("ars");
    bankDetails.setBranchName("noida");
    leadDetailSRO2.setBankDetails(bankDetails);
    Set<String> deleteSet1 = new HashSet<>();
    Set<String> deleteSet2 = new HashSet<>();
    Set<String> deleteSet3 = new HashSet<>();
    deleteSet1.add("bankDetails-beneficiaryName");
    try {
        System.out.println("Before deletion object 1 is : " + leadDetailSRO1 + " object 2 is : " + leadDetailSRO2+"deleteset A is : "+deleteSet1+" B is : "+deleteSet2+" C is : "+deleteSet3);
        Utils.mergeObjectAndSet(leadDetailSRO1, leadDetailSRO2, deleteSet1, deleteSet2, deleteSet3, null);
        System.out.println("After deletion object 1 is : " + leadDetailSRO1 + " object 2 is : " + leadDetailSRO2+"deleteset A is : "+deleteSet1+" B is : "+deleteSet2+" C is : "+deleteSet3);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

The output is :

After deletion object 1 is : LeadDetailSRO{uploadDocumentList=null, businessOwnerDetails=null, businessOwnerDetailList=null, authorizedSignatoryList=null, businessEntityDetails=null, leadInfo=null, bankDetails=null, addressDetails=null, cfaAgent=null, vaAgent=null, auditTrail=null, additionalDetails=null, additionalQuestions=null, documents=null, agentDetails=null, timelineDetail=null, nocStatus=null, docAcceptanceMap=null, slabDataList=null, userConfiguration=null, userKycDetailsSRO=null, mandatoryParams=null, cmtParams=null, pgParams=null, bankInstrumentSROList=null, creditBankFacilitiesDetails=null, disbursementDetails=null} object 2 is : LeadDetailSRO{uploadDocumentList=null, businessOwnerDetails=null, businessOwnerDetailList=null, authorizedSignatoryList=null, businessEntityDetails=null, leadInfo=null, bankDetails=BankDetailSRO{bankName='null', bankAccountNumber='null', ifscCode='null', bankAccountHolder='null', beneficiaryName='ars', branchName='noida', status='null', nameMatchStatus='null', reEnterAccountNumber='null', reEnterIfscCode='null'}, addressDetails=null, cfaAgent=null, vaAgent=null, auditTrail=null, additionalDetails=null, additionalQuestions=null, documents=null, agentDetails=null, timelineDetail=null, nocStatus=null, docAcceptanceMap=null, slabDataList=null, userConfiguration=null, userKycDetailsSRO=null, mandatoryParams=null, cmtParams=null, pgParams=null, bankInstrumentSROList=null, creditBankFacilitiesDetails=null, disbursementDetails=null}deleteset A is : [bankDetails-beneficiaryName] B is : [] C is : []

Whereas the expected output is :

After deletion object 1 is : LeadDetailSRO{uploadDocumentList=null, businessOwnerDetails=null, businessOwnerDetailList=null, authorizedSignatoryList=null, businessEntityDetails=null, leadInfo=null, **bankDetails=BankDetailSRO{bankName='null', bankAccountNumber='null', ifscCode='null', bankAccountHolder='null', beneficiaryName='ars', branchName='noida', status='null', nameMatchStatus='null', reEnterAccountNumber='null', reEnterIfscCode='null'}**, addressDetails=null, cfaAgent=null, vaAgent=null, auditTrail=null, additionalDetails=null, additionalQuestions=null, documents=null, agentDetails=null, timelineDetail=null, nocStatus=null, docAcceptanceMap=null, slabDataList=null, userConfiguration=null, userKycDetailsSRO=null, mandatoryParams=null, cmtParams=null, pgParams=null, bankInstrumentSROList=null, creditBankFacilitiesDetails=null, disbursementDetails=null} object 2 is : LeadDetailSRO{uploadDocumentList=null, businessOwnerDetails=null, businessOwnerDetailList=null, authorizedSignatoryList=null, businessEntityDetails=null, leadInfo=null, bankDetails=BankDetailSRO{bankName='null', bankAccountNumber='null', ifscCode='null', bankAccountHolder='null', beneficiaryName='ars', branchName='noida', status='null', nameMatchStatus='null', reEnterAccountNumber='null', reEnterIfscCode='null'}, addressDetails=null, cfaAgent=null, vaAgent=null, auditTrail=null, additionalDetails=null, additionalQuestions=null, documents=null, agentDetails=null, timelineDetail=null, nocStatus=null, docAcceptanceMap=null, slabDataList=null, userConfiguration=null, userKycDetailsSRO=null, mandatoryParams=null, cmtParams=null, pgParams=null, bankInstrumentSROList=null, creditBankFacilitiesDetails=null, disbursementDetails=null}deleteset A is : [bankDetails-beneficiaryName] B is : [] C is : []

LeadDetailSRO is a class which contains BankDetailSRO within it as an object and BankDetailSRO contains fields beneficiaryName,branchName.