Membership doesn't connect user to supporter

Dear WPMU-Dev Team,

I have installed Membership V2.0.7 and Supporter V2.2.8 on a Multi-User Network. Membership Plugin is activated for the main site (not network wide).

I created different membership levels Premium and Premium Pro.

For Premium Pro levels, the membership/supporter button is enabled!
When a user goes through the membership subscription, the subscription for membership works fine, but the user is still not supporter.

Whats wrong? Is there something, I have to activate before it works?

Best regards