Hiya,
Having a look at your site, I do see there’s some issues with outdated JavaScript in use on your Divi theme, you should see if there’s an update to the theme, the jQuery Migrate Helper plugin will help with those, for now, but the icons missing is a font issue.
Basically, a server setting appears to not allow you to reference the font files directly from https://www.[yourwebsite].be, only form https://[yourwebsite].be (without the www. in front), so the icons they include can’t be loaded.
You may need to contact your host about that, if you’re not familiar with setting access headers your self. If you do contact them, you should be able to reference the following error:
Access to font at 'https://[yourwebsite].be/wp-content/themes/Divi/core/admin/fonts/modules.ttf' from origin 'https://www.[yourwebsite].be' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.
