How can I require user to save form as a different document?

I have a pdf form I have created in Adobe Acrobat Pro.

I want users in my office to be able to access the form on the server. But then once they open the form and fill in fields, I want to require them to save their form as a different document --- so as not to override my clear form on the server.

Currently, they can fill in fields / Hit save / then this save over my clear form.

Things I have tried:

• I have tried to change the "properties" of the fields to "read only". But then, when you open them, a user cannot fill the fields at all.
• I have tried changing the "Document Properties" to "Password security" and then selecting to "restrict editing" but that seems to also prevent the user from filling in the fields.

Thank you!