Yup, im having the same problem. It fixes itself for a bit when I restart my phone, but then goes back to flipping upside down. Very frustrating
@Members_dr3qSZ3: Does your issue occur while you're using a particular app, or is it persistent? To troubleshoot the situation, please try placing your phone on a flat surface, swipe from the top of the screen to the bottom and tap on Auto rotate so it locks to Portrait mode, then tap it again to re-enable Auto rotate. With the phone still resting on a flat surface, swipe from the top of the screen to the bottom, then again to enlarge the Quick Panel, then tap the Power button in the top right and select 'Restart'.
Im having the same issue on S21 5G. I can also confirm that the actual sensor is flipped by using a leveling app. It clearly shows that the "left/right" sensor is flipped as the levelling bubble moves the wrong way.
So its not an app misreading something. It happens on Youtube and other streaming apps. In the levelling app.
Not sure how to see the software version. But oneUI 5. 0, Android 13. Installed updates when prompted to.
The error is not isolated to a single app.