Custom Domains Clarification

Looking for some clarification on custom domains.

I have a domain lets call it my-domain. From here, I have various applications deployed across many sub-domains of this domain. For example, an application in a staging environment might be found at and other applications in staging may be at I’ve configured my Auth0 Custom Domain as ( per the docs on custom domains). Will this enable the required cookies to be used across all subdomains of Furthermore, I’d like to double check that these same cookies would not be able to be used in the non-staging subdomains, i.e. (Without staging. subdomain).

More generally, is the cookie acquired from valid for * and invalid for * otherwise? Am I thinking about this wrong?