I had this problem with my P20 pro where everytime I opened a pdf file in my ‘files’ app, it would open a default program Adobe Fill & Sign. After that, there’d be 2 of the same file in my ‘files’ app. I would have to go to the optimiser, cleanup and manually delete duplicate files everytime I’d see them.
Today, almost 2years later, I decided to try another app as my default pdf opener, I downloaded Adobe Acrobat Reader from the app store. Viola my problems are solved. I deleted the Fill & Sign app and am much happier.
Have any of you had a similar problem? Would like to know.