@Lexus Because my code is the latest and has changed a lot of things. The latest version of the code was uploaded to github yesterday. I just verified with the vim4-android-11-64bit-v221228 version of firmware. When I plug in the USB camera and open it with the camera application that comes with the system, the default is the rear camera.
In addition, as I said before, the Android code itself opens the rear camera by default. I suspect you have reversed the front and rear.