I can view my pdfs (made from scans) on my Android tablet just fine, but the text search function doesnt find results. My Samsung Tab 2 uses Acrobat Reader 15.2.1. I am however able to properly search the same files on my Win 7 laptop using Reader XI. Related question - should I use Acrobat DC on the tablet instead?
Searching on scanned files is not completely supported on Adobe Acrobat. Would it be possible for you to share the problematic PDF with us at firstname.lastname@example.org so that we may take a look at the issue?