Users other than 'admin' unable to access iControl REST API

Hi all. We're running 12.1.x and users other than 'admin' are unable to access the iControl REST API. Our users authenticate through AD. Users in the same role group as the admin user cannot access the API while the admin user can. We also tried creating a local account and adding it to the same role group as the admin user and it also cannot access the API.

Is there some specific configuration that needs to be completed to allow access to the REST API to users other than the admin user?

Thanks, Pablo