Bình luận chính thức
From the terms email:
SINGLE APP CONNECTION
DJI only allows a single app to be connected to an aircraft at any given time. If another app is already connected, you need to terminate that app in order for Map Pilot to function properly.
This very well may be the cause of your gray camera preview. Also, there was a quicky update that fixed a camera issue if you are talking about the version that was released for about 8 hours.