Hope you are doing well.
When you switched the computer, ho did you transfer the files from one computer to another?
Transferring the file must have been through some backup drive/ device or Cloud storage?
In such data transfer application doesn't play any role. As long as you haven't used the Document Cloud storage and file disappeared from there.
Just to double check you may login on Document Cloud web and check if you have your PDF files.
Also, you may check whether you have logged in into the application using your same old Adobe email or not.
Other than that if you have lost anything in data transfer through harddrive, that is something we cannot trace.