Anonymous user appears logged out on page refresh

When signing-in as anonymous, refreshing the page makes the user appear signed-out. If another sign-in is attempted, such as signing-in as admin, the UI shows that the sign-in was successful but the server thinks that anonymous is still signed-in.

Steps to reproduce:

• Sign-in as anonymous
• Refresh page (UI thinks the user is signed out)
• Sign-in again as admin

Signing-in as another user does nothing more than change the username in the header. Because `anonymous` didn't sign-out, the server still thinks that the `Subject` is anonymous. So signing-in as admin doesn't show the cog if the previously signed-in user was anonymous.

Attached video shows defect: RefreshClearsAnonymous.mov