Sorry to hear you are experiencing problems with the app. The only other time we have head of this happening it turned out to be that the DJI Go app was running in the background while Map Pilot was running. This will cause a lot of issues if that is the case and it is always important that you only have one application attempting to connect to the drone at one time.
If that isn't that case and you are absolutely sure that the Go app was fully shut down, let us know exactly what kind of data card you are using. We are triggering the camera as fast as it can possibly be triggered and if you have a slightly slower data card that isn't fast enough to keep up, there is a good chance this is the behavior that would be seen. You may be able to record video just fine the way we trigger the camera needs a fast card.