I am experiencing some odd behavior around the logout process in Drupal 8. When I am logged in as admin and then logout, using either the Drupal "Log out" link or by appending "/user/logout" to the url, I am redirected to my Microsoft log out page. If I click the browser back button, I go back to the page I was on, and the Drupal admin toolbar is still visible. If I click any of the links on the toolbar, I get a 403 so, I am definitely logged out. Somehow, the toolbar is remaining in the cache.
I've searched for mentions of this issue but haven't come up with anything. Thanks for any help or suggestions.