How to certify a PDF so that it remains compliant with PDF/A-3u?
We are using Acrobat Pro DC's preflight feature to convert PDFs to comply with the PDF/A-3u standard. Our next step is to use Acrobat Pro DC to digitally certify the same PDF. Once that is done, Acrobat Pro DC reports that the file no-longer complies with the PDF/A-3u standard.
Here is a screen cap of the preflight indicating the issue.
Is there a way to certify PDF/A-3u files that doesn't break conformance with the standard?
I asked this same question in the PDF standards forum here. The conclusion was that Acrobat Pro DC is breaking the PDF/A-3u standard when it signs the file. Any suggestions as to how we can overcome this issue or is it simply a bug in Acrobat Pro?

