I can’t login into to an online account or play online. All other games on my Switch are working with online except Fantasy Strike. When I try to login it says “Disconnected from the server.” Immediately after pressing the login button.
We very briefly had an outage of online play on Nintendo Switch. It was quickly fixed. Possibly you tried to play right then. It should be working now, and for the last few days too. If not, let us know.