Hi Patrick,
This is supposed to be helpful information, but you may see it as not. For what it is worth, there is no such issue on any of my machines., Windows 10, Debian 9, Ubuntu 18.10 and Mac OS 10.13.6 High Sierra. So at least we know the docs do work for at least one person!
I will add that there are _very_ weird problems with the Mac and the Mac only with the font Alegreya, and only Algreya, in which text just does not show. And some people see this and some do not. It's very strange. You read the threads on this - pure mystery. I mention this because it is another observed strange font problem on Mac.
A usual suggestion, but can you upgrade your Mac to a more recent version of the OS? I understand there may be reasons preventing you, but it may help, and I don't know how far back the lilypond developers support Mac OS.
Andrew