When I installed Xournal++ from the official repositories, it would export blank PDFs, without either my annotations or the original document. Installing the Flatpak version fixes the issue. Therefore, I’m guessing this is related to a library that Xournal++ depends on. Could someone please look into this issue and see if they can replicate it?
I can export annotated PDFs perfectly (Manjaro XFCE, stable channel). Can you open xournalpp from the command line and post the output?
Also please post the output of inxi --admin --verbosity=7 --filter --no-host --width