I am experiencing what I think may be a new feature, but possibly not, when you open a .pdf and update it, then using the back button exit the .pdf which auto saves it, when you next select on the same .pdf it somehow opens the original unedited version but as a new document with a number in front of the .pdf, e.g. 2.pdf, each time you update and save the .pdf and open it again a new file is opened. - Is this the correct/expected operation - I am expecting to open the same/updated document each time not the original unedited version, can this 'new' feature be switched off? - From reading other Q&A's I think this is being seen by other users but they are assuming that updates to the .pdf did not save as they are presented with a blank/original .pdf when they re-open the .pdf following a save.
Adobe Acrobat v17.5.180092 used on a Samsung Galaxy Tab S2 Android v7.0
Thanks for your interest.
We understand your problem.
Please answer few of my queries that will lead towards the resolution of this issue.
Can you please tell us more about the workflow you are following, specifically the source of file (local/document cloud/gmail etc.) and the modification that you are making to the pdf. If the source is gmail, then creation of new replicas of the same pdf is an expected behaviour.
Adobe Acrobat Team