All browsers require fonts to be hosted on the same domain and a subdomain is considered a separate domain name. If your font awesome icons or custom fonts are not showing up in a certain browser, below is the solution for you:
Open .htaccess file in an editor and add codes below. You can find the file in the root directory of WordPress installation.
<IfModule mod_headers.c>
<FilesMatch "\.(ttf|ttc|otf|eot|woff|font.css|css)$">
Header set Access-Control-Allow-Origin "*"
</FilesMatch>
</IfModule>Note: You can access to website directory thought Cpanel or using an FTP software. In most of the servers, it’s in the public_html folder.