We are currently using Diagnostics 9.50 version.
Browser remembers your username and password and tells the site when it comes back that it was logged in
If the logout is not implemented then the session will not expire after closing the browser and the other user/attacker can take advantage of this and use the logged-in user account.
It is recommended to:
1. Logout should be implemented to avoid misuse of user account.
Thanks & Regards,