Unexpected OOTB login screen when using the browser "back" button
So we have an anonymous user acces configured and a button to allow for anonymous user to switch to a "real" operator-based connection. This button is actually performing a log off (in order to log off as an annonymous user) which ends up in display the login screen (which is a custom login screen).
Problem is: after clicking on this button and landing on the customized login screen if the user is clicking on the browser back button, the system ends up displaying the OOTB login screen. While of course we would need it to display the custom one.
I think I understand what's going on: the previous page the user is trying to get back to using the browser back button is a page where he was logged in as a anonymous user. But we explicitly log off from this anonymous session so there is no more anonymous requestor here so the system falls back to displaying a login screen. Unfortunatley it is the OOTB one it's displaying and I can't understand what to do to fix it.
Any idea/clue/help welcome.