I faced the problem after updating One UI 5.0. I have made the test of gyroscope and accelerometer. They are both failed. Autorotation mode became absolutely useless, camera and other apps turns the picture on the wrong side.
How to fix? #galaxys21+
Got exactly the same problem after the update. Fast fix is restart the phone, but after 3-5 hours the problem appears again.
Wipe cache partition brings up to 6h,but still not fixed completly
Same issue with my Note 20 Ultra. Looks like this is firmware problem. Because I don't believe that our accelerometer broke in our phones in one time in different countries
I have exactly the same problem since 5.0 update and nobody from Samsung gives any answer or solution.
There are many people posting about this problem and there are several threads about this issue on samsung. Hopefully they fix it on a coming update.