How to how to get the checked checkbox in recyclerview while getting onQueryTextChange?

I have set up a recyclerview, in which there are there views, Countryname, currency, and checkbox. I dont need to provide dataset for checkboxes because i can get the corresponding countryname anyway when they are clicked. But the problem is, i have implemented a searchview, and it works fine. But whey i check the corresponding checkbox, it checks that box at positioned relative to TOP.

public class RecyclerViewAdapter extends RecyclerView.Adapter <RecyclerViewAdapter.ViewHolder>  {

    Context mcontext;
Data dataclass;
    List<alldata> Rclist=new ArrayList<>();
    private int lastCheckedPosition = -1;
    List<String> countries= new ArrayList<>();
   RecyclerViewAdapter.ViewHolder HOLDER;
    View itemV;
   int pos;
    public RecyclerViewAdapter(List<alldata> list, Context context) {
        this.Rclist= list;
        this.mcontext=context;
        for (int i=0; i<list.size(); i++) {
            countries.add(list.get(i).country);
        }
    }

    @NonNull
    @Override
    public RecyclerViewAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_view_row,parent,false);
        ViewHolder holder = new ViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(@NonNull final RecyclerViewAdapter.ViewHolder holder, final int position) {
        holder.country.setText(Rclist.get(position).country);
        holder.currency.setText(Rclist.get(position).currency);
        holder.checkBox.setChecked(position == lastCheckedPosition);
      this.HOLDER=holder;
      this.pos=position;
    }
    @Override
    public int getItemCount() {
        return Rclist.size();
    }

    public void updatelist(List<alldata> newList) {
            lastCheckedPosition = HOLDER.getAdapterPosition();
       notifyDataSetChanged();
        Rclist=new ArrayList<>();
        Rclist.addAll(newList);
        notifyDataSetChanged();

    }


    public class ViewHolder extends RecyclerView.ViewHolder {
        TextView country;
        TextView currency;
        CheckBox checkBox;

        public ViewHolder(@NonNull final View itemView) {

            super(itemView);
            country=itemView.findViewById(R.id.country);
            currency=itemView.findViewById(R.id.currency);
            checkBox=itemView.findViewById(R.id.checkBox);
                checkBox.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        itemV=itemView;
                        lastCheckedPosition = getAdapterPosition();
                        //because of this blinking problem occurs so
                        //i have a suggestion to add notifyDataSetChanged();
                        //   notifyItemRangeChanged(0, list.length);//blink list problem
                        notifyDataSetChanged();
                        CharSequence text = currency.getText() + " is now the selected currency";
                        int duration = Toast.LENGTH_SHORT;
                        Toast toast = Toast.makeText(v.getContext(), text, duration);
                        toast.show();
                    }
                });
        }
    }

// in activity

  public class selectcurrency extends AppCompatActivity implements SearchView.OnQueryTextListener {

    List<String> countries= new ArrayList<>();
    private static String TAG="";
    RecyclerView recyclerView;
    RecyclerViewAdapter adapter;
    List<alldata> list=new ArrayList<>();
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.dashboard, menu);
        MenuItem searchmenu= menu.findItem(R.id.search);
        SearchView searchView = (SearchView) searchmenu.getActionView();
        searchView.setOnQueryTextListener(this);
        return true;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_selectcurrency);
        //   sharedPref = this.getSharedPreferences( MY_PREFS_NAME, Context.MODE_PRIVATE); editor = sharedPref.edit();
        Data obj=new Data();
        list=obj.getData();
       Collections.sort(list, new Comparator<alldata>() {
           @Override
           public int compare(alldata o1, alldata o2) {
               return o1.country.compareTo(o2.country);
           }
       });

        for (int i=0; i<list.size(); i++) {
            countries.add(list.get(i).country);
        }


   initRecyclerView(list,this);
    }
    private void initRecyclerView(List<alldata> list, Context context1) {
        List<alldata> List=list;
        Context context=context1;
        recyclerView = findViewById(R.id.recyclerView);
        adapter = new RecyclerViewAdapter(List ,context);
        recyclerView.setAdapter(adapter);
        LinearLayoutManager gridLayoutManager= new LinearLayoutManager(context);
        recyclerView.setLayoutManager(gridLayoutManager);

    }


    @Override
    public boolean onQueryTextSubmit(String query) {
        return false;
    }

    @Override
    public boolean onQueryTextChange(String newText) {
        String userinput= newText.toLowerCase();

        List<alldata> newList=new ArrayList<>();
       for (String country: countries) {
           if(country.toLowerCase().contains(userinput)) {
            newList.add(new alldata(country,""));
           }
       }

        adapter.updatelist(newList);
        return true;
    }

}

images are at https://imgur.com/a/1xAw7xi