I have a persistent problem with Acrobat Reader on Android, and its interaction with Dropbox. If I open a .pdf from Dropbox in Acrobat Reader, and then make annotations in it in Acrobat, the result is *never* saved automatically. If I want it saved, I have to manually "share" it to "add to Dropbox" etc.
My understanding is that it ought to save automatically, and that this is the point of Adobe/Dropbox integration. I'm running Android 7.1.2, with the latest versions of the Acrobat and Dropbox apps. Does anyone else have this problem?
Sorry for the delay in response.
As per the issue description mentioned above, annotation made on the pdf file (opened from Dropbox) in Acrobat Reader doesn't get saved automatically to dropbox, is that correct?
Try unlinking dropbox account by tapping on the Dropbox>tap three vertical dots in the top-right corner.
Manage Dropbox Accounts>Unlink>tap OK.
Relaunch app> add dropbox account and try again.
Also, share the version of Acrobat Reader app installed on the device.
Keep us posted with the results.