You can check for issues with (corrupted) fonts. You can right-click and select "Inspect" to open the built-in Inspector with this element selected. *https://developer.mozilla.org/en-US/docs/Tools/Page_Inspector/How_to/Examine_and_edit_HTML You can check in the <b>Rules</b> tab in the right panel in the Inspector what font-family is used for selected text. You can check in the <b>Fonts</b> tab in the right panel in the Inspector what font is actually used because Firefox might be using a different font than specified by the website. *https://developer.mozilla.org/en-US/docs/Tools/Page_Inspector/How_to/Edit_fonts