S21 ultra Won't unlock

[Raystaray]

My S21 ultra wont unlock at all. Before it kept restarting and from last night it restarted and it wont unlock even when I type in the password, it just goes black and then comes back to the lock screen. I have tried to restart it by using the volume and power button and it restarts but once it comes back to the lock screen and I enter the password again, it just go black again and goes back to the lock screen. 

Why is this happening and why wont it unlock. I dont want to do factory reset because I have alot of important files that I need keep and I want to back them up but I cant do that without unlocking the phone. Any ideas?

[Bjonge]

Did you find a solution? My phone s21 got stuck this morning, and only ask for pin..

[Android_Gal521]

My S21 Ultra has been going crazy also since the last few updates. The screen doesn't let my fingerprint or PIN open my phone it just kicks back to the login screen after freezing or going black. My keyboard won't come up at all. I can't restart or power off the phone because when I hold the buttons down to the screen just flickers and locks back up. I'm totally locked out of my phone! I definitely am not doing a factory reset...I own a corp and can't lose my info. I've always raved about Samsung and I've never owned another phone...but this is making me consider a Google phone or something (except iPhone)