This can happen if you block remote fonts that are downloaded from internet or otherwise block website fonts. Make sure you allow pages to choose their own fonts. *Settings -> General -> Language and Appearance -> Fonts -> Advanced<br>[X] "Allow pages to choose their own fonts, instead of your selections above" If you use uBlock Origin make sure not to "block remote fonts". ---- These days a lot of websites use an iconic font to display small images. If you disable website font via "Allow pages to choose their own fonts, instead of my selections above" then such fonts are disabled and you may see little boxes with the hex code of the character or text labels instead.