When I tried to use landscape right as described in Unity - Manual: Player Settings, then the navigation bar appeared on the wrong side.
Actually the navigation bar should be on the left side as the graphic is rotated clockwise.
This also leads to funny rotations when Unity starts and when it returns to the Android screen. Can I have landscape right and the navigation bar remains where it belongs?
By the way, the Amazon Firestick behaves similarly: when choosing landscape right, lots of rotations happen.
The scenes themselves are as they should be, my world is not upside down. It is just the navigation bar and the switch between the Android screen and the Unity Player which are not that beautiful.