Tax Lookup in Sales Order

Our sales rep often uses Copy function to duplicate a previous sales order. We experienced sales tax issue when we do so recently.

If the order was created previously when sales tax nexus had not be enabled for a state, when sales rep Copy that Sales order, then the new copied sales order would have -not taxable- tax code for all the items in the sales orders, even though the customer is taxable, and nexus has been turned on for that shipping address.

It seems that there is no way to let the system look up tax code in this scenario. Sales rep has to either manually choose a tax code, which is basically impossible for them to select a correct tax code, or sales rep has to delete that item and add it back to the sales order to trigger NetSuits to look up the tax code.