"All things related to preferences, time stamps and storing name/password
pairs is done by Cookies which are stored and handled by the browser.
If these things "don't work" then the browser very likely is set not to
accept cookies for more than a "session" - aka until all browser windows
are closed.

The problem is not with your server or the application, it's a matter of
the software (browser) settings on the users end.
They must set their browser to accept "permanent" cookies, not only
session cookies. "