Created attachment 130846 [details]
Okular displays some extended ASCII characters like umlaut o/u properly in annotation boxes (e.g. pop-up note) but not inline.
STEPS TO REPRODUCE
1. Open a PDF document with Okular, and switch to Review mode.
2. Try using such characters via Typewriter, Inline Note and Pop-up Note tools.
For example; although all characters are displayed well in the pop-up boxes, some characters such as "G/g with breve", "I with dor above", "dotless i" and "S/s cedilla" are not displayed at all. Some characters such as "umlault O" and "umlault U" are displayed simply as O and U. On the other hand, there's no such problem with "umlaut o/u" and "C/c cedilla".
All those characters should be displayed properly inline as well.
Linux/KDE Plasma: Kubuntu 20.04
(available in About System)
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8
*** This bug has been marked as a duplicate of bug 305534 ***