I had a similar thing happen recently following a NixOS upgrade. I wonder if it’s something that changed in Firefox.
In my case, the solution was to set useEmbeddedBitmaps = true
in fontconfig. Which is unlikely to be directly helpful to you on Fedora, but maybe there’s an equivalent option somewhere?
“Cable elves”? Ridiculous.
They’re called machine elves, and if you want those pictures to come out you’ll have to load that camera with DMT.