After installing the [https://addons.mozilla.org/en-GB/firefox/addon/native-mathml/ Native MathML] extension (to get MathML typeset equations on the Wikipedia, as suggested on [https://www.mediawiki.org/wiki/Extension:Math#Viewing_math mediawiki.org]), all equations set by MathJax/MathML turned to using STIX instead of Latin Modern. I'd like them to stick to Latin Modern instead. The only possibly related setting I've found is `font.name-list.serif.x-math` in about:config, whose value is `Latin Modern Math, STIX Two Math, […]`. I tried to manually change the font family specification of some text to see if Firefox could use Latin Modern Math to begin with, but apparently it can't (see first screenshot attached), while it loads STIX allright (second screenshot). Latin Modern is not the first locally installed typeface I haven't been able to use, but it's the first one I have really tried to (I don't remember which one the other typeface was). My Latin Modern font comes from TeX Live 2019 installed using the TUG installer, not Fedora's package manager. `fc-list | grep -i "latin modern math"` returns `/usr/local/texlive/2019/texmf-dist/fonts/opentype/public/lm-math/latinmodern-math.otf: Latin Modern Math:style=Regular`. I'm running Firefox 87 on Fedora 33.