Initially I though that maybe it only worked in the larger font sizes, as I usually have it set to Tiny, but it appears as it’s reverting to some sort of default plain font at all sizes.
Assuming the display icon of the font is a representation of what the font is supposed to be.
I thought the same; that perhaps it was specific to a font size but came up with the same results as you. Like you mentioned as well, I do assume the font is supposed to look like the icon for it as all the others seem to be a preview but it’s appearing like a basic rounded version of a San Francisco-ish type font.