SUMMARY As the title saying. ADDITIONAL INFORMATION I'm refereed from GitHub of flatpak version on FlatHub to post this issue here after discovering the real nature of this issue - see: https://github.com/flathub/org.kde.okular/issues/67 See specially the following: https://github.com/flathub/org.kde.okular/issues/67#issuecomment-673992274 Best.
Works fine for me https://i.imgur.com/MjZIsvj.gif
It is not working with Arabic characters. When path to the image contain Arabic characters, the stamp does not working .... By the way, even if I used English characters & stamp added okay, I noticed that it will disappeared if I change location of original image or delete it from my disk !! Is this intended (or what you call experimental) ?!
> It is not working with Arabic characters. Still works for me.