Please consider going over to your dial pad and type in *#0*#, this will bring up a number of tests to try.
If they don't help then seek support from a Samsung Experience Store or Samsung Service Centre.
Current Phone ~
Samsung Note 20 Ultra 5G SM-N9860_256Gb SnapDragon 865+
Samsung One Ui 3.1/ Android 11.
Bought the phone back in 2019, used the camera almost every day to login to whatsappweb for work and read QR codes. Two /three weeks ago started getting the blurry / out of focus problem. Now need to get a new phone as I can't log in to Whatsappweb anymore and cannot read QR Codes !!!
No new apps added to phone, I have tried every suggested fix I can find on the internet.