My rear-facing camera has a white screen. All of the other functions in the camera work well. I can reset the camera settings however, I cannot take pictures because it's just a white bright screen that shows up on all the pictures.
it sounds like the Rear Cam module is completely open wide and exposed, hence flushed with light and everything is white in your screen. Unless you are using pro-mode and purposefully opening your exposure, this shouldn't be happening.
Take the phone to UbreakIfix and have them diagnose your cam, see if it's damaged/defective. If they say it's fine, then try submitting an issue report to Samsung Members app after reattempting to take picture with the rear cam.]
by the way, is ALL the rear cam lens showing white screen? change the zoom and see if other lenses are fine.
My note 20 Ultra phone is under warranty until February 27th 2022.