Ember Simple Auth immediately invalidates the session after authenticating with Torii

I am trying to set up Torii with my own OAuth flow and Ember-Simple-Auth. I can get a successful authentication event, but immediately after I authenticate, the invalidateSession trigger is fired causing my session to end. I can see this by intercepting sessionInvalidated() in /app/routes/application.js (which has the ApplicationRouteMixin).

Have any of you come across this? Is there something peculiar that would cause an immediate session validation? Any advice would be greatly appreciated.