I am flying Drone Deploy on a Mavic Pro connected to an iPhone 7. I have no issues executing the flight plan or capturing images, but I am no longer receiving a video feed of my flight. It used to be that in the upper right hand corner the little box would show what the camera was seeing and turn black for a half second when an image was captured. Now, it is just black the whole time.
8/24/18
Mavic Pro with current firmware
iPhone 7 , 11.4.1
2.78.0
That seems to happen once in awhile. Usually landing and recycling power on the drone and controller clears it up.
That worked! Thanks, Gary.
I have the same trouble, i fly mainly with iphone (6 i guess) and without any video feed 
When i fly on my android, not trouble, but i prefer iphone as it have the manual flight option (and i use it).
Almost all my flight a multi battery, after a switch, the feed is back but for 2-3min max then freezes…
All my software are up to date.