Unable to create website outside of the org

wav3front

I'm testing Enhance.

I have created a customer and a package. Package has no limitations.
When trying to create a subdomain dev.domain.com (via the customer account) I get:

Failed to add 'dev.************.com': Unable to create website outside of the org

Nickske00

Is domain.com owned by the org? It's probably a security feature so users can't create subdomains for domains owned by other users (not sure it's the case here because I have not enough information from the topic start).