Yesterday I was testing the FPV CAMERA app's Mission Control and set a trajectory that took my P3P beyond tall buildings where I lost both the video feed and RC signal. I waited to see if it would complete the mission as advertised . . . and waited . . . and waited until I feared that the battery would run out. The failsafe altitude was set to 300 feet because of buildings around the HP, and I couldn't see it anywhere around me. I decided to press the RTH button on the controller, which started beeping, but after several minutes still the bird was nowhere to be seen. In desperation, I switched to the DJI GO app and . . . lo and behold, I regained video signal and saw that it was approaching the HP spot from the failsafe altitude. I have (1) a concern and (2) a question. Why would the bird not complete the mission? How can the bird have received the order to return if the RC signal had been lost? I know it obeyed RTH and did not complete the mission because of the direction from which it appeared. Also, I find it interesting that I could run the two apps simultaneously, despite FPV CAMERA's instruction not to do so.