Invalid Google Authenticator codes are displayed because of the incorrect device clock settings. 


Your clock must be synchronized with the correct local time, date and time zone to work appropriately. 


Android and Windows phones have an option to correct the time errors inside the Authenticator app. 


iPhones must be set to use the internet time to make sure the clock is synced. 


Use 2FA on your account, and never store more than you intend to trade on any exchange.