Hello!
Me's been experiencing this, too but me doubts it's something worth concerning about. I don't think it's someone hacking into your account so no need to worry!
It could be a confirmation thing, like some sites do when they have you type in your information twice. It could be used as a precaution to fool those who may try to log into your account by giving off the same result it would do if you've typed in your information incorrectly. If that makes sense?
However, I cannot say with 100% certainty. This is just my theory. I am also unsure on if this happens to every user or if it is, indeed, a newborn glitch.