S6 rejecting correct password?

[Lioelle]

After my phone battery dies, it requires me to put in my password rather than use the fingerprint sensor to unlock - this would be fine, except recently it's starting rejecting the correct password, and locking me out of my own phone. I can be locked out for 60 minutes at a time by repeatedly trying to use the correct password ... I don't know what is going wrong with it.
On other occasions, I have managed to unlock it simply by trying the password over and over again, but this time, it doesn't seem to be working at all ....
Has anyone else had the same problem? Is it some kind of glitch?
I'm definitely using the right password - like I said, sometime it would work, but now not at all...
I really have no idea what to do ....
There is no option popping up to unlock by google account either.

 

[B. Diddy]

Welcome to Android Central! Are you entering the backup password you created when setting up the fingerprint sensor, or a password you previously created if you had the lockscreen set to Password? I think they can be different.

Another possibility is that the onscreen keyboard is glitching, and not typing the characters you're pressing. You could try connecting a basic USB keyboard via OTG adapter, and enter the password that way to see if it make a difference.