HI there,
It is because maybe you have saved those details on you browser. Your browser will intelligently know that field is password and fill those form as you have save it. Maybe you can try to remove those save forms(username and pasword) and see how it goes
By the way, if there still an issues, you are no need to change a new actually, you just need to remove those filled in password only and you are good to go(save your edited profile)
Please advice.