I am able to receive and display push notifications and in-app messages in my Android app and that works correctly.
However, even though I check the "Combine With Message Center" checkbox, the message center is empty. I tried various combinations of message types and content. The out-of-box message center screen (UAirship.shared().inbox.startInboxActivity) always displays "No Messages", and whenever I work with UAirship.shared().inbox, it always has 0 messages (tried addListener, tried calling fetchMessages, but no effect).
What could I be doing wrong? I am using Urban Airship Android SDK 9.5.6.