Problem loading fonts via USS resource (2019.3.0a8)

EDIT: Problem solved. I wasn't paying attention to the list of applied stylesheets in the debugger. Turns out my path for the stylesheet itself was wrong.

I'm trying to load fonts via resource ("path") method in uss stylesheets and not having much luck.

Here's my situation: I have a style class named fa-solid:
.fa-solid {
-unity-font: resource("FontAwesome/Solid.ttf");
}

This is supposed to find the font file under Resources/FontAwesome/Solid.tff. Except it can't. The path works with a Resources.Load<Font> call on the C# side but not with uss resource. I've tried it with and without file extension; makes no difference. Below is a screenshot of the UI element inspected with UIElements Debugger:



The element is assigned the correct class, but the font is still the default one.

What am I doing wrong here? Am I misunderstanding how style class hierarchies work? Is uss resource busted?