API Key not working for subdomain

[Application28108962k7nb]

So I've got an API Key for our application domain [ex: domain.edu], and it says in the account that “Your Client ID (API Key) is restricted to this domain, plus any subdomain.” We also have a staging environment [staging.domain.edu], but when trying to use the API key in staging I get the error "This application domain (https://www.staging.domain.edu) is not authorized to use the provided PDF Embed API Client ID." Can anyone help me understand why it isn't actually working in staging?

[Application28108962k7nb]

At the bottom of this (https://community.adobe.com/t5/acrobat-services-api-discussions/using-pdf-embed-api-on-multiple-doma...) conversation, an employee says "Also, if your dev/staging/production are all something.foo.com (dev.foo.com, staging.foo.com, www.foo.com), you can just make a key for foo.com." But this is exactly what isn't working for me, unless I'm missing something.

[Test Screen Name]

Looks, though, as if you have a sub-sub-domain (staging.domain.edu is a sub-domain but www.staging.domain.edu is a sub-sub-domain). I don't know if that is the issue, but it seems a possibility.