Not authorized for app after 5.6.6 upgrade

I just upgraded my development instance to 5.6.6 from 5.6.0.  This is on my local machine using a developer's license, forms-based authentication, and authentication is disabled on the app.  My account is local and an administrator in PU. Under 5.6.0 I was able to access the app.  After the upgrade I now get an 'Unauthorized' message trying to access the app. Oddly, I can successfully access the other local app that is using the same authentication configuration. Any idea what happened? I would like to push out the upgrade to my testing and production instances but those actually use OpenID Connect so I don't want to break access to my other published apps that actually rely on RBAC. 
The app logs don't show any issues, and I have still not found where you can troubleshoot logs for authentication and access.

Product: PowerShell Universal
Version: 5.6.6