Hi Steve,
We just tested the AppAuthDemo app against a Gluu server 3.1.3 and it works well.
See the video in attachment.
Can you provide a video like that where we can monitor the process step by step and sees at which point it fail.
Another quick way to tackle that will be to provide us the following information so that we that test directly against your AWS instance:
1. The hostname of your gluu instance
1. A test user we can use to login
1. Client detail(clientID, redirecturi)