MacOS Big Sur. Problems with typography

You should be able to reset Apple Type System (the font registry) from Font Book. If not, you can do the same thing from the command line in Terminal (generally caches shouldn't be cleared - but obvious issues with the font registry like ? appearing in places of the glyphs is an execption).

atsutil databases -remove

Go to the Font Book app and check the settings for a place where you can Reset All Fonts or something similar