Multisite subdomain-site redirects to primary site

If you;re wildcard subdomain is redirecting to the main site, then the wildcard setup on the host is incorrect. Or they do not support it.

Setting up the wildcard in the DNS records is not the only step. Some shared hosts do not support it or require a dedicated IP address.

Also if you’re trying this on an add-on domain and not the main domain of the web account, it also will not work.

So it’s not the config file or the htacess at all. You really need to ask your webhost.