We use PDFNet to convert PDF files to PDFA. When we highlight some text in the pdf files, using Adobe Acrobat, and the document is converted to PDFA, the highlight loses its transparency, and obfuscates the text. We can’t read the text any longer.
We are using PDFNet with Level1B Conformance setting.
PDFA Level 1 conformance restricts PDF’s to PDF Version 1.4, which did not support transparency.
Instead you should switch to Level 2B conformance, which supports PDF Version 1.7 (and therefore transparency).