I have a P3 and P4. Cant get an FPV connection on my P4 with my ipone 6s or my android tablet. On my Android when I plug P4 in it identifies it as P3 on home screen and there is no option to switch it like I can on iPhone. On the IPhone it connects nut says no video transmission signal in red at top of screen. What I suspect may be issue is that I stupidly put an old SD card in P4 that had an old P3 firmware update on it. I think it may have updated some firmware on camera. Gimbal will not move at all from remote. I have tried to do firmware updates through the app and assistant 2 but they don't work. Is it possible to do a P4 upgrade through the SD card like the P3. Any other suggestions?