EditText content is repeating every 4 list item in a Listview

Question

I am trying to make a sales screen using listView where each listItem has an editText for user to input sales quantity for that particular item. I am using an Array Adapter to generate the listView. Problem is, when I click on an editText (for instance, position 1), type something in it and scroll down, every 5th (position 5, 9, 13 and so on) editText is getting focused and the typed content is automatically getting repeated in those editTexts. Tried a lot of online resources, but not able to find out what am I doing wrong! Thanks in advance for any help.

class SalesEntryAdapter extends ArrayAdapter<SalesEntry> {
    List<SalesEntry> mList;
    public SalesEntryAdapter(List<SalesEntry> salesList) {
        super(SalesActivity.this, R.layout.listview_sales_item, salesList);
        this.mList = salesList;
    }

    class ViewHolder {
        TextView tv_itemCode;
        TextView tv_itemDescription;
        TextView tv_priceLot;
        TextView tv_tradePrice;
        TextView tv_discPrice;
        TextView tv_salePrice;
        TextView tv_qtyOnHand;
        TextView tv_lineTotal;
        EditText et_saleQty;
        int position;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        final ViewHolder holder;
        LayoutInflater inflater = getLayoutInflater();
        double trade_price, net_price;

        if(convertView == null){ // ensures re-usability of views created runtime
            convertView = inflater.from(getContext()).inflate(R.layout.listview_sales_item, parent, false);
            holder = new ViewHolder();
            holder.tv_itemCode = convertView.findViewById(R.id.tv_itemCode);
            holder.tv_itemDescription = convertView.findViewById(R.id.tv_itemDescription);
            holder.tv_priceLot = convertView.findViewById(R.id.tv_priceLot);
            holder.tv_tradePrice = convertView.findViewById(R.id.tv_tradePrice);
            holder.tv_discPrice = convertView.findViewById(R.id.tv_discPrice);
            holder.tv_salePrice = convertView.findViewById(R.id.tv_salePrice);
            holder.tv_qtyOnHand = convertView.findViewById(R.id.tv_qtyOnHand);
            holder.tv_lineTotal = convertView.findViewById(R.id.tv_lineTotal);
            holder.et_saleQty = convertView.findViewById(R.id.et_saleQty);
            convertView.setTag(holder);

        }
        else{
            holder = (ViewHolder) convertView.getTag();
            //convertView.setTag(holder);
        }


        SalesEntry salesEntry = mList.get(position);

        holder.position = position; // save the position in the ViewHolder
        holder.tv_itemCode.setText(salesEntry.get_item_code());
        holder.tv_itemDescription.setText(salesEntry.get_item_desc());
        holder.tv_priceLot.setText(salesEntry.get_price_lot());
        holder.tv_tradePrice.setText(Double.toString(salesEntry.get_trade_price()));
        holder.tv_discPrice.setText(Double.toString(salesEntry.get_net_price()));
        holder.tv_salePrice.setText(Double.toString(salesEntry.get_net_price()));

        holder.et_saleQty.setText(Integer.toString(salesEntry.get_sale_qty()));

        //holder.et_saleQty.setId(position); // this is to set a reference ID for each EditText

        trade_price = salesEntry.get_trade_price();

        /*
        holder.et_saleQty.setOnFocusChangeListener(new View.OnFocusChangeListener() {
            public void onFocusChange(View v, boolean hasFocus) {
                if (!hasFocus){
                    int position = v.getId();
                    EditText saleQty = (EditText) v;
                    //salesList.get(position).sale_qty = Integer.parseInt(saleQty.getText().toString());
                }
            }
        });
        */
        return convertView;

    }
}