The same issue which camera is blurry with my samsung s8+. It is definitely the hardware issue, Samsung should look at it and resolve asap.
The workaround is shaking the phone.
The fix for the problem and it totally worked for me. I bought an app from the play store called HD Camera Pro. Now this camera has a option in settings called callibrate camera. Put your s8 or s8 plus flat on a table and press callibrate. It takes only a second. You will notice the blur is gone on HD Camera Pro and all camera apps. Your Samsung camera will also work perfect again. Let me know if it solved any of you guys camera.