@Davide, I want to point out that giving the file a name is what you, personally, are talking about. What both @sharpdrivetek and I have been pointing out is that Manager’s temporary name for a file that has not yet been saved and your operating system’s name for the saved file are two distinctly different things.
As I already said, you have made it very clear you wish Manager to assign a name differently than it does. You want to be able to save the PDF file directly with Manager’s assigned name and have it be comprehensible. I understand that. But giving a name to the saved file is still within your total control.