Wrong quantity when using "Multiple Rows" to add item

As discussed in this issue incorrect qty added on Purchase order if user tries to add multiple items · Issue #23880 · frappe/erpnext · GitHub, the quantity remains 1 if we use the multiple rows button to add items to child table in Quotation.

Please guide if there is a solution for this bug.

I tried adding

frappe.ui.form.on('Quotation', {
    refresh: function(frm) {
        frm.get_field("items").grid.set_multiple_add("item_code", "qty");

but no use.