When exporting to pdf it creates a document with all previous exported documents

This one is kind of hard to explain and I don't think I've seen this happening to anyone before.

I'm an IT guy and I've been having this issue with a couple of users. When you export (print) from any document (Word, Excel, etc) to Acrobat reader it sends it ok, but it doesn't create a new document for the exported file. It just adds it up to a pdf document that has all previous exported files going back a couple of months making it a 200+ page pdf everytime you try and print it doesn't matter how you name it, rename it, etc.

I've tried deleting temp files and adobe cache, reinstalling... the usual.

We are using PDF995 as our printer driver and we haven't had this issue with all users, just a couple here and there.

OS is Win 7 and Adobe Acrobat Reader DC

Hope any of you have some sort of answer I really have no idea