Android Studio CheckBox Proble

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

DoctorsModel list;


Context context;
Activity activity;
ChangeFragments changeFragments;

public UserAdapter(DoctorsModel list ,Context context, Activity activity)  {
    this.list = list;
    this.context = context;
    this.activity = activity;
    changeFragments = new ChangeFragments(context);
}

@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

    View view = LayoutInflater.from(context).inflate(R.layout.usersitemlayout, parent, false);
    return new ViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull final ViewHolder holder, final int position) {

    holder.userName.setText(list.getDoctors().get(position).getFullName());
    Picasso.get().load(list.getDoctors().get(position).getImage().getUrl()).into(holder.userImage);



    holder.ChechKadin.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if (holder.ChechKadin.isChecked()){
                Toast.makeText(context, "True", Toast.LENGTH_SHORT).show();

            }else {
                Toast.makeText(context, "False", Toast.LENGTH_SHORT).show();

            }
        }
    });

}


@Override
public int getItemCount() {
    return list.getDoctors().size();
}

public class ViewHolder extends RecyclerView.ViewHolder {
    TextView userName;
    CircleImageView userImage;
    CheckBox ChechKadin,ChechErkek;


    public ViewHolder(View itemView) {
        super(itemView);

        userName = itemView.findViewById(R.id.userName);
        userImage = itemView.findViewById(R.id.userImage);
        ChechKadin = itemView.findViewById(R.id.CheckKadin);
        ChechErkek = itemView.findViewById(R.id.CheckErkek);

    }
}

}

public class UsersFragment extends Fragment {

private View view;
private ChangeFragments changeFragments;

private RecyclerView kullaniciRecylerView;
private DoctorsModel list;
private UserAdapter userAdapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    view = inflater.inflate(R.layout.fragment_users, container, false);
    tanimla();
    getKullaniciler();
    return view;    }

public void tanimla()
{

    changeFragments = new ChangeFragments(getContext());
    kullaniciRecylerView = view.findViewById(R.id.userRecylerView);
    RecyclerView.LayoutManager layoutManager = new GridLayoutManager(getContext(),1);
    kullaniciRecylerView.setLayoutManager(layoutManager);
    list = new DoctorsModel();

}

public void getKullaniciler()
{
     Call<DoctorsModel> req = ManagerAll.getInstance().getUser();
    req.enqueue(new Callback<DoctorsModel>() {
        @Override
        public void onResponse(Call<DoctorsModel> call, Response<DoctorsModel> response) {

         //  list = (DoctorsModel) response.body().getDoctors();
             list = response.body();
            userAdapter = new UserAdapter(list,getContext(),getActivity());
            Log.i("kullaniciler",response.body().toString());
            kullaniciRecylerView.setAdapter(userAdapter);
        }
        @Override
        public void onFailure(Call<DoctorsModel> call, Throwable t) {

            Toast.makeText(getContext(), "HATAA:...!!", Toast.LENGTH_LONG).show();

        }
    });
}

}