If you’re logged out and reading a thread, you should be able to login in another tab and then do a forced refresh (control-shift-R); and it should show the thread with logged-in control. For some reason the cookie isn’t being passed or (perhaps more likely) the cookie is insufficient because Lemmy is using some mechanism other than cookies.

Scenario 2:

You’re logged in and reading threads in multiple tabs. Then one tab becomes spontaneously logged out after you take some action. Sometimes a hard-refresh (control-shift-R) recovers, sometimes not. It’s unpredictable. But note that the logged-in state is preserved in other tabs. So if several hard refreshes fail, I have to close the tab and use another tab to navigate to where I was in the other tab. And it seems navigation is important… if I just copy the URL for where I was (same as opening a new tab), it’s more likely to fail.

In any case, there are no absolutes… the behavior is chaotic and could be related to this security bug.