Did you added this code on your .htaccess file.
# Allow access from all domains for webfonts.
# Alternatively you could only whitelist your
# subdomains like “subdomain.example.com”.
Header set Access-Control-Allow-Origin “*”
You can find similar query on searching Eample https://stackoverflow.com/questions/11616306/css-font-face-absolute-url-from-external-domain-fonts-not-loading-in-firefox
Best Regards!