QSvgWidget renders (some) images wrong

At least some SVG images are rendered incorrectly. Open `svg_file.svg` in e.g. firefox. The image should look like a two headed arrow (<->). Now download `main.cpp` and `qt_svg_bug.pro`, open the project, compile it and start the executable . Select `svg_file.svg` in the file dialog. The image is displayed clearly incorrectly (compare with `qt_svg_bug.png`).

I've not tried Qt versions other than 6.8.3 and 6.9.1.