@Anders_ASUS Does it flip all the way? Does it seam to flip att normal or reduced speed? Is this behavior with our camera app? - yes it flips all the way at normal speed. Yes with Asus camera app. If the phone is exposed to small vibrations during flipping, it might flip slower (more controlled) but it should still flip all the way unless it feels/believes that it could damage the camera if it continues. You shouldn't flip and drive 😉 - not flipping whilst driving but when is mounted on the support for the Android Auto.
It could be that there is something mechanically wrong. Best way to find out is to reset your phone. If it doesn't help, then you need to send it for service. - sometimes it flips but cannot take a picture, then it flips again by itself and allows the picture to be taken. - Also sometimes the message "cannot flip" appears on the screen but the camera is flipped and a picture can be taken.
Sounds weird. That message normally only appear when the proximity sensor is covered or dirty but then it should't flip. I still say, that you should try a reset first and if it doesn't help, then you need to send it for repair.