There is a feature in acrobat reader which takes you to the first page of pdf when to touch the top of screen regardless of where you are in the pdf. This seems to be an absolutely useless feature which actually creates problems rather than solving anything! Please remove this feature. Thank you.
Also while saving something that I wrote using the Apple Pencil it gets kind of scruffed/edgy/blurry. So please look into that as this problem is not there with apple apps like photos and notes.