Which version of the app are you using? I have 3 Lemmy accounts, and one of them was doing this (or something similar) for me in 0.37. I would log in fine, but if I switched to another account and back, it would say "anonymous" and I kept getting "network error."

But I got version 0.38 from f-droid today and that problem and several other ones I had are gone. (Although, I did have to log out totally and back in on that account to fix it.)

Same issue on Fdroid 0.38 today. Just getting started on Lemmy but it's practically unusable as it keeps telling me to log in first when I try to do anything. And there's no easy access to accounts/config so you have to back right up to the login screen. For a new user it's hard to tell if issues are a Lemmy issue or a Jerboa issue because there are multiple servers involved. This is my third try with this comment so fingers crossed.

Edit: sorry Jerboa, but I have switched to Connect. No complaints with it. I'm sure I'll give Jerboa another try when it's more mature, but not being able to log in is a deal breaker!

Likely not related at all, but I've found that some apps will let me log-in with just my username and password--others require my email addr & password.