Domain Mapping and CORS origin Issue

I have a problem with icons on one of my sub-domains which I've that mapped to bld****** I suddenly noticed that the search icon on the header menu turned to U symbol and other icons turned to some other character. I don't know how to fix this. I use Divi theme on the subdomain. Here is the subdomain:*****

There is the following error in browser console:
Access to Font at '' from origin '' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin '' is therefore not allowed access. The response had HTTP status code 403.

I've tried to fix this via htaccess Access-Control-Allow-Origin rules, but it doesn't help.