The problem was that the properties were not populated with values. Apparently if a value is null it is not returned. Seems an odd behavior given that many other (unrelated) properties on the response object are null, empty, or undefined.
How to get custom attributes from claims?
Sam Wheat
406
Reputation points
This document describes steps to select user attributes to appear in claims token:
You should now see ShoeSize in the list of attributes collected during the sign-up journey, and see it in the token sent back to your application.
After following above steps custom attributes do not appear in the token sent back to my application. What am I doing wrong?