As the title says, FF seems to selectively forget cookies and thus requires me to constantly re-login.
I’ve had the exact same issue on two separate machines both running Ubuntu. My best guess is, that snap is at fault here, but I have no idea, why.
To reproduce the issue, I just have to perform the arcane ritual of “closing the app” and whoosh, cookies are gone. Plugins and settings persist, no “delete on close” option whatsoever is active. Vanilla Ubuntu shows exactly this behavior.
I have a similar issue (also Firefox on [K]ubuntu 22.04) every time I open a link on a logged-in site in a new tab, but in my case merely refreshing the page is enough to get me logged back in.
I assume is most likely the fault of the fairly aggressive mix of extensions I’m running rather than Firefox itself, but I haven’t actually tried to troubleshoot it yet.