Windows 10 Home 1903, Photo 1.7.1.404 and Designer 1.7.1.404.
As part of an experiment I (fairly randomly) found an SVG https://pixabay.com/vectors/car-black-vehicle-transport-travel-311713/ that I wanted to use but upon opening it in Photo and Designer (haven’t bothered trying Publisher) I see that it hasn’t been imported correctly. A lot of the detail is missing and there are bigger issues – see attached snapshots from Designer and Photo.
It’s not a big problem for me as I can use the raster version instead but I thought I’d mention it so someone can look into it (there’s a chance that the original SVG is to blame so it might not be an Affinity problem).