How to reconnect a social account from the iOS app
If you change the login details for one of your social accounts, you will need to reconnect it to Buffer. You can do this from the iOS app by tapping the round avatar icon at the top left of your screen and selecting the social account which needs reconnecting. From here, tap Settings and then tap Reconnect this Account. That should prompt you to reconfirm your password and once you've done that, you should be all set!