Nosto supports multiple subdomains under one primary domain and an account, but primary domain and front page’s url needs to be set separately.
Under Account settings define your store’s front page’s url including protocol definition (http / https) and the primary domain separately.
Please note that the primary domain is defined without protocol and subdomain prefix, such as “www”. Example definitions for primary domain.
Correct: nosto.com
Incorrect: www.nosto.com