Apply user rights to data base with mu

In the documentation for the tenats, an example is shown for multiple applications (multiple Idiciums) linked to a single data base is shown. 

Where each application has there own tenants

URL: https://docs.thinkwisesoftware.com/docs/iam/tenants 

We have created two applications, one for the operations and one for requesting data through the API.

Where each applications has there own tenants, with different names.

Now if we want to apply user rights to database, we get the following error message;

“Could not apply rights for the application because there are multiple tenants assigned to the application”

I can't find what I'm doing wrong in this instance.

Can someone explain what I have to change, in order to setup the two application correctly, that I can apply the rights to the database.