We've got a weird problem with Adobe DC saving files to a Windows 2012 server. If you open a pdf (or create one from a file) add a comment \ sticky note and save it the creation date is as it should be. If you reload it and remove the comment and save, the creation date then gets updated with the modified date.
It doesnt do this if you work with files locally, only with pdf files on the server. I tried Foxit-Phantom to see if it was server related and Foxit worked fione, so it seems to be Adobe DC related?