UNI warns you that your sign-in has ended at most once between one sign-in and the next. If it drops a second time before you have signed back in, nothing appears on screen. The page goes on looking normal and your next action fails without saying so.
That is the behaviour, not a fault with your account.
The warning comes from a failed request, not from a timer
Nothing on UNI watches the clock and tells you when your sign-in ends. The message "Your session has expired. Please log in again." is produced when a request the page makes is rejected by the server. So it reaches you at the moment you next do something, not at the moment the sign-in actually ended.
Two conditions have to hold for it to show:
- The warning has not already been shown in this browser tab.
- Your browser still holds a cached copy of your signed-in account. Showing the warning clears that copy.
Because showing it clears the copy, the second condition fails on every rejection after the first. Signing in again restores the copy and rearms the warning.
What a silent drop looks like
- Buttons stop responding. Save, Like and Follow do nothing visible.
- Lists load empty, or your own work stops appearing on pages where it should.
- The header can still show your avatar, because that part is drawn from the cached copy rather than from a fresh check with the server.
What to do
- Reload the page. A reload asks the server directly, so a sign-in that has ended shows as signed out.
- Sign in again.
- Redo whatever failed. An action rejected for being signed out was not saved, and nothing was saved halfway.
Making the sign-in last longer
Select Remember me on the sign-in screen. Without it, your sign-in ends when you close the browser. With it, the sign-in lasts a day, and every page you open on UNI extends it by another day from that point.