I noticed that I can create a notebook on Android from a picture file. On my iPad I regularly do that and then add more picture files to the notebook. But when I share the notebook and try to open on Android or Windows that does not work. When creating a notebook from a PDF file it works a charm.

I use Goodnotes as a digital puzzle magazine and copy/past puzzles from a newspaper.

Maybe I missed something but can't seem to get sharing a notebook made up from picture files working