I don’t think I am being clear.

I can’t find any of the attachments in the first place. Do you understand what I’m saying?

With QuickBooks 2016, I used to be able to search my computer or my iCloud for a customer’s name and the PDF attachment from inside the attachment library would come up in Finder or the Files app on my iPhone. 

no, I cannot find those files at all. The attachment library is a file itself, not a directory like it used to be.