Old thread, but I hit the SVG import problem. I completed a test to become a drone pilot and the license card was downloadable in SVG. After importing into Affinity Designer 2, it looked not even close. The QR code was misplaced etc.
It imported fine in Inkscape, but exporting it again to SVG or PDF did produce something that Affinity Designer 2 think is blank.
The solution I found was to run a command line tool that I assume cleaned up and/or normalized the SVG to something Affinity Designer 2 is ok with
brew install librsvg
rsvg-convert -f svg -o dronecard_cleaned_up.svg dronecard.svg
kent