Hi, What happens: Open a browser tab Log in with user A Open in the same browser a 2n tab I see the login page and I log in with user B Here comes the question. With Mx 4 and at least up to 5.8.1 I end up with being logged in as user B. In the 2nd tab I am immediately user B and in the first tab when I refresh the tab I am user B as well. However with Mx 5.20 I will be user A in the 2nd tab, despite the login. In the first tab I stay user A. Why the difference? It is the same application but what has changed, besides the Mendix runtime? I checked all release notes for session, cookie and login/log in/log-in but only 5.13 mentions something that might come close (Fixed that users can resume their existing session after the platform has been restarted when persistent sessions are enabled (ticket 204678). Regards, Paul