Overview:
The Vault auto-numeric value in the document name is different than the auto-numeric value in the document number.
Root Cause:
There is a token that can be used in the document naming convention that allows it to contain the same value as the current document number.
Solution:
Use the Document Number token ({document_number__v}) in the document naming convention in order for the current document number to be reflected in the document name.
Related Documentation:
Vault Field Documentation: Managing Document Numbering
Thank you