duplicate item in recycleview

I am use recycle view to show a list of item from room database. the recycle view is reside in a fragment, when I navigate to fragment for the first time the items appear duplicated twice, but when I click in a button inside item, all items appear at once as desired. this is my adapter this is my adapter.

    private Context context;
private List<Product> productList;
private BroojDB database;

public CartAdapter(Context context, List<Product> productList) {
    this.context = context;
    this.productList = productList;
    notifyDataSetChanged();
}

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

    View view = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.cart_recycle_item,parent,false);
    return new MyViewHolder(view);
}

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

    Product product = productList.get(position);
    int count = product.getCount();
    float productPrice = product.getPrice();

    float subTotal = count*productPrice;
    database = BroojDB.getInstance(context);

    holder.count.setText(product.getCount()+"");
    holder.title.setText(product.getTitle());
    holder.price.setText(product.getPrice()+" SD");
    holder.subTotal.setText(subTotal+" SD");
    holder.deleteProductFromCart.setBackgroundResource(R.drawable.cancel);

    holder.increaseOne.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            Product p = productList.get(holder.getAdapterPosition());

            int pId = p.getId();
            String pTitle = p.getTitle();
            float pPrice = p.getPrice();
            int pCount = p.getCount();

            pCount++;

            database.productDao().updateProduct(pId,pTitle,pPrice,pCount);
            productList.clear();
            productList.addAll(database.productDao().getAllProduct());
            notifyDataSetChanged();

        }
    });

    holder.decreaseOne.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Product p = productList.get(holder.getAdapterPosition());

            int pId = p.getId();
            String pTitle = p.getTitle();
            float pPrice = p.getPrice();
            int pCount = p.getCount();

            if (pCount >=1)
            pCount = pCount - 1;

            database.productDao().updateProduct(pId,pTitle,pPrice,pCount);
            productList.clear();
            productList.addAll(database.productDao().getAllProduct());
            notifyDataSetChanged();
        }
    });

    holder.deleteProductFromCart.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            Product p = productList.get(holder.getAdapterPosition());
            database.productDao().deleteProduct(p);

            int position = holder.getAdapterPosition();
            productList.remove(position);

            notifyItemRemoved(position);

            notifyItemRangeChanged(position,productList.size());

        }
    });


}

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


public class MyViewHolder extends RecyclerView.ViewHolder {

    Button increaseOne,decreaseOne,deleteProductFromCart;
    TextView title, price,subTotal,count;
    public MyViewHolder(@NonNull View itemView) {
        super(itemView);
        increaseOne = itemView.findViewById(R.id.increase_product_one);
        decreaseOne = itemView.findViewById(R.id.decrease_one);
        deleteProductFromCart = itemView.findViewById(R.id.remove_item);
        title = itemView.findViewById(R.id.item_title);
        price = itemView.findViewById(R.id.item_price);
        subTotal = itemView.findViewById(R.id.sub_total);
        count = itemView.findViewById(R.id.count_off_product_in_cart);

    }
}