My Galaxy tab s4 does this all the time. I know the password but it keeps telling me it's wrong and it says biometrics can't be used till next time. If this is the case and YOU KNOW your password IS CORRECT, just reboot the tablet. Hold the power button down for 3-5 seconds and when the prompt comes up to turn off or reset, choose reset. YOUR PASSWORD WILL WORK ONCE IT COMES BACK ON. This is the only thing that works for me. My mother in law lives with us and has the same tablet and she never has this issue, so it is not every tablet.