magento 2 credit memo set “quantity to refund” column value as 0 by default

i want to set “Qty to refund” column value as 0 by default and then i will update qty for only those product which i want to refund.
i tried to set value as 0 but after that the “Update Qty” button does not update the qty and again set the quantity as 0.

is there any solution to fix this?

Thanks in advancde.