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