This issue mostly happens when WordPress isn't correctly set up or the website was migrated and the old URLs are still present in the database.
Number 3 shows up because Divi serves the fonts via a file, called modules.woff. If for some reason the font file isn't accessed on that path on the web server, the raw content(in this case '3') is returned instead.
Reasons for the modules font file being blocked
mixed content -> This is a common problem when moving a website over from HTTP to HTTPS.
In general, the various resource URLs (like images, videos, fonts, etc.) that you have in your content and are stored in the database need to be replaced.
The easiest would be to use a plugin such as Better Search Replace. More info about how to work with the plugin and fix the mixed content errors can be found here
Wrong WordPress setup > in Settings -> General, WordPress Address (URL) and Site Address (URL) need to match the HTTP protocol. If your website has an active valid SSL certificate, the address needs to correspond with HTTPS -> preview
Blocked by the web server -> In certain cases, your web host may, for various reasons, restrict access to the font file when it's requested in the browser.
This could be due to permission settings or other factors. It's advisable to reach out to your web host and inquire if they have blocked access to the font file.