My s21 is showing a white screen when I'm in normal zoom mode on rear camera but works very zoomed in or out. It happens from 1.0x to about 3.9x or 4.0x. I had the cameras replaced and this didn't solve the problem.
Are you using a third party camera app? If not, maybe try one and see if the problem still occurs. If it does, it's likely a hardware problem. If you are using a third party app, try uninstalling and use the default camera app.
