Access denied message shown when user is entitled to access, but only on initial login

If a user goes to /saml_login from a page where they have received an access denied message they still see the access denied message after they have logged in, even if they have the appropriate permissions. However, if they refresh the page, navigate away and then back, or simply try to access the same page again they will have all the access they are entitled to and not see the access denied message again.

This seems to have something to do with caching of permissions. It could be happening because the user is being redirected to these pages from the IdP directly. Perhaps there is an issue with the way the user is initialized by the simplesamlphp_auth module. Do they have all the right roles immediately?