Disconnects and Unable to log on to game, or view webpage (sometimes)

[Saneko-ragnaros (Saneko)]

@Náia-argent-dawn

Account info has been changed

Account information has changed

Hello i just got this message and disconnect “You have been disconnected because your account information has changed. (BLZ51900062) ” I never saw this error so dont know what happen or what to do. I have ultra strong password, physical authenticator bought in 2012 (yes still working) and phone protect. Nothing was changed in my account and i can log in back.