A specific pdf file (attached) is not rendered correctly in Okular (seen in version: 1.9.3 and 21.0.4) which uses poppler. In my understanding we are talking about quite basic characters like lower quotes " and minus - The Okular team's analysis (https://bugs.kde.org/show_bug.cgi?id=437613) point to an issue in poppler. The affected PDF and the screenshot of what is wrong displayed: Linie_160_Laufdor_Am_Sportplatz.pdf