How do I enable or disable service (proxy) subdomains?
You can enable service subdomains (formerly known as proxy subdomains) via the "Service subdomains" setting in "WHM » Home » Server Configuration » Tweak Settings." Conversely, you can disable service subdomains if you disable this setting.
You can read more about service subdomains here:
Please note that it is not possible to selectively disable service subdomains. You can alter the "Zone Templates" so that they do not resolve.