I’ve used the Adobe Reader on my iPad for a year or so, and I have never had any trouble losing comments. In the last week I’ve added comments to files and lost them after closing the file. I’ve attempted to save it to the document cloud, but nothing works. I updated to the most recent version this morning (20.01.00), but that does not help.
I can open files that I modified a few months ago, and those comments are still present. It only seems to affect files with recent comments.
I am having the same problem with Acrobat Reader DC on a Mac. It appears to have started after the February update. I marked up a PDF page proof to answer questions and clean up typos, then saved, but nothing showed up either in my saved copy or in the copy I sent to the editor. It appears that the February security update only saves comments if the Comment sidebar is open, something that was not required before.
I worked on a PDF using comments and saved the document under the different name. For some reason the document has disappeared form the folder, and i can only find it when i search for it in my Documents. Unfortunately the PDF cannot be opened - Adobe fires an error message. Is it possible to retreive the lost document? Otherwise it is a waste of the whole day work!