I am running Okular Version 21.12.3 on Kubuntu 22.04. I have PDF documents with pop-up notes that were created in Adobe Acrobat Reader, on Windows. When I open those documents in Okular, I can see the highlighted text where the pop-up notes are, but clicking on it or selecting it doesn't open the note. It seems that Okular doesn't recognize the notes, only the highlighting.
Is there a way for them to be displayed in Okular, or is there another Linux program that can do this?
Show navigation panel, go to the reviews. There you should get a list of all of them.
Popup notes unfortunately don't show directly. You have to hover the mouse over it and wait a few seconds. In the code, I also found this comment:
Alternatively, in the review pane, right click on an item, select "Open Pop-up Note".