Actually, the problem doesn't seem to be the system using the font file, but the system
generating the font file. The font files that one system generates is bad, but the other two system generate good font files. Must be a bug in one of the FontForges or, more likely, one of the dependencies.
Here, I figured out how I can link non-image files: the
good, the
bad and the
template. Where do I submit bug reports?