this is the image

The screenshot didn't attach.

Could you please give it another try?

You can check in Font Book for font issues like corrupted and duplicate fonts. You can try to do some maintenance.

• https://appletoolbox.com/2016/07/fix-corrupt-user-accounts-macos/

See also these threads about font issues.

• /questions/1292109 Fonts replaced with question marks in boxes
• /questions/1268528 when I type the number 9, the underscore symbol appears (long dash)
• /questions/1278708 Text of website https://apod.nasa.gov/apod/ is missing the charakters x, y, z but only in lower case where x is not simply missing but replaced by "

this is what i get on some site's

You can right-click and select "Inspect Element" to open the builtin 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 Rules tab in the right panel in the Inspector what font-family is used for selected text. You can check in the Font 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