If your icons are not displaying correctly on the IDX Broker page it is usually because of the server settings that block downloading fonts from your website via external server (some hosting may block it e.g. to protect premium fonts). How to fix it?
1. Please modify .htaccess file in your root server (e.g. via File Manager https://wordpress.org/plugins/wp-file-manager/)
2. Backup the file
3. Add this code at the top of a file
Header set Access-Control-Allow-Origin "*"
4. Save a file