I am on the iOS app. When I try to upvote a post on a site of which I am already a member, the following string of events happens:
It thinks I am not a member, so it asks me to join. But since I am a member, it throws an error. If I click Cancel, nothing happens.
I have been using the app often and frequently. This is the first time it has happened. The only difference is that I am in a different state at the moment. (In case something is tied to GPS, figured I'd provide that information.)