radio button recyclerview

gistfile1.java

abstract class RadioAdapter<T> extends RecyclerView.Adapter<RadioAdapter.ViewHolder> {

    public int mSelectedItem = -1;
    private Context mContext;
    private List<T> mItems;

    public RadioAdapter(Context context, List<T> items) {
        mContext = context;
        mItems = items;
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, final int i) {
        viewHolder.mRadio.setChecked(i == mSelectedItem);
    }

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

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        final View view = LayoutInflater.from(mContext).inflate(R.layout.view_radio_item, viewGroup, false);
        return new ViewHolder(view);
    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        public RadioButton mRadio;
        public TextView mText;

        public ViewHolder(final View inflate) {
            super(inflate);
            mText = (TextView) inflate.findViewById(R.id.text);
            mRadio = (RadioButton) inflate.findViewById(R.id.radio);
            View.OnClickListener l = v -> {
                mSelectedItem = getAdapterPosition();
                notifyItemRangeChanged(0, mItems.size());
            };
            itemView.setOnClickListener(l);
            mRadio.setOnClickListener(l);
        }
    }

}

I used the tutorial above. I have 3 radio buttons. when I checked on the 4x radio button it couldn't be checked but in the log it managed to bring up the index and text of the radio button