I use the android apk "Thunder" for lemmy and since yesterday I couldn't post, reply, or vote, even though I was signed in. A few hours ago I had to clear the cache and the data on the apk and log back in to make everything work again. Never had to do that before. I'm guessing this issue with the instance and update had something to do with it.
same here: my "subscribed" timeline showed all kinds of posts from communities I never heard of. Only in my app (Boost) though. resetting the app fixed it.