Cant no longer change OWA's signature

Adrian_0102 
This is so frustrating that they would roll out this option of allowing multiple signatures, but fail to update an admin's ability to manage them. Even when accessing a user's' mailbox in the browser that i have full access to, it still only shows me the old interface where i can only set the one signature. But when they access the very same page inside OWA themselves, they can access and use multiple. 
Good idea in theory, but just very bad execution. And the fact that the multiple signatures is still not sufficiently documented anywhere is just horrible. Huge fail by the team rolling this out.