How to avoid having the packing slip number on shipment and still ship confirm?

Summary:

We are doing a cloud to cloud migration. In the old instance ship confirm is happening without pack slip number. But in new instance it is throwing error

The Ship Confirm process can't obtain a document sequence setup for the packing slip to generate a new document number. Review the document sequence, document sequence assignment, and document sequence category setup for the packing slip

The only difference in configuration i see is in "Manage Ship confirm Rule", Under this
Old instance: Packing slip status is "Blank"
New instance: Packing slip status is "Final" (It does not allow me to edit, is there any way to make it blank)?