honestly, even i went off of lemmy for a bit, not because i dont like lemmy, but because every time i reloaded the page, it would sign me out, and i couldn't save any settings, it seems to be happening across most lemmy instances right now
That happened due to the emoji vulnerability. One mitigation step admins had to take is rotate JWT secrets, which essentially deauthenticated everyone's sessions.
Lemmy-UI and some 3rd party applications didn't know how to react to that, as this is not an official Lemmy feature (it required a database query), so they stayed in that limbo state you're describing here.
Just log out and back in. If the problem persists, delete the cookie for your instance and try again.
I haven't seen that issue. I use browser mostly (even on mobile). Sometimes use liftoff. Never had an auth issue. Maybe something with the larger instances?