When opening a PDF exported from Affinity using other apps, the space characters are all gone. They are rendered visually by increasing the spacing ("tracking") between last/first characters of each word.
I was able to replicate this bug by opening an Affinity PDF in Illustrator, Inkscape, CorelDraw, and Sketch, all on macOS. I've had this issue only with PDFs generated by Affinity, so it's definitely an issue with the Affinity apps and/or PDFlib.
This issue is important because it affects the way we can exchange files with people who don't use Affinity apps. Until now, opening an Affinity PDF in other apps seemed like a good enough solution whenever I needed to convert an .afdesign file to .ai or something else. This bug makes it very difficult to exchange files containing more than a few sentences of text, without manually reformatting the text.
Please fix it.