Was this slways an issue or did it start after a security or OS update? If so there are a couple of troubleshooting steps you can try. First, clear the camera app's cache and data: open device settings (cogwheel icon)>apps>camera>storage>clear cache/data>force stop>restart phone. The other is performing a partition cache clear which is good for cleaning out software bugs. Here are the steps: https://www.hardreset.info/devices/samsung/samsung-galaxy-s20-ultra-5g-sd865/wipe-cache/ If neither of these steps help it may be a hardware problem and it may need to be looked at by a repair center service tech.
Im having the same problem with my s21 ultra. I reset it and still the same. What you can do to fix the blurry temporarily is to knock a few times the side of the phone where the camera is against your hand before you take a photo.
