Default warehouse selection even though no warehouse is set in stock settings or item master

Hi Team,

Please help me out on this, i have not selected default warehouse neither on the item master nor on the stock settings still it is catching up by default a source warehouse in sales order.

Now when i am creating pick list from a different warehouse still in the delivery note it is catching up the same source warehouse mentioned in sales order which is creating a lot of trouble to the client.

It is much better if source warehouse in sales order would be blank and whatever is mentioned in pick list should be used as source warehouse in delivery note.

Check the Item Group and Brand defaults as well