Please follow the steps below to troubleshoot the issue:
1-check if there is an available update via :settings>software update>download and install
2-Press the volume down button and the power button for 10 seconds, the phone will restart
go to Settings> Applications, then find the app, choose Storage, and clear cache then Go to the Camera app, then choose Settings and reset the camera settings
and please run a test via Samsung members app> go to Support -> Diagnostics>then camera if the test result is action required unfortunately in this case you need to visit Samsung service center
