New DocType - duplicate

Hello everyone.
I have created a new document. Being the first approach, I simply duplicated Delivery Note to create an equal one in all the main aspects. But, when I create the new document, many relationships are missing.
For example, I enter a customer and the currency seems disconnected, as well as the address and the table items are connected only the codes.

How can I duplicate a document and make only small changes such as numbering and printing format?

You can change by Customization. No need to duplicate an entire doctype.

Please specify the customizations you wish to do so that community can suggest you options

I have already customized the documents. There are no problems on this aspect.
I wanted to create 2 comelli to be used for different prints, each one with its dafault numbering. And other small changes already parameterized.