The issue at hand isn’t that your website is getting CORS errors, it’s that your website is trying to access our 403 Forbidden page in the first place.
Please check which URLs are being accessed on your website that redirect to the 403 page, and try to figure out (and fix) why that happens. This guide may have some useful pointers:
If you need help figuring this out, please clearly state which URLs are triggering the 403 response.