Not able to change UOM On packing List

We are able to choose any related unit on quotation/sale order/delivery note and it is auto picked on the next doc too.

We are facing below error

a) While creating packing list from draft delivery note it picks up the quantity for ml but show UOM as default one in Litre, so packing slip shows 100 litre for while it should be 100 ml.

Any thoughts on where we are doing it wrong.