Hope you are doing well. Sorry for your experience with Acrobat Reader Mobile.
Did you scan to create the PDFs you are referring to? If yes, please check if you have used the option "ID" to scan the file. That would lock the file, and you would need to manually unlock the file from your end to enable other users to access the files.
If not, please share the file with me over a private message ( click on my profile name-> click the blue button that says "Send a message" on the next page) for further investigation.