I just bought a new Phantom 4 and have taken it out 6-7 times so far. Everything worked perfectly fine until today, when I went up to 100m and suddenly lost connection. It came back down on its own and I picked up the signal again at around 80m, but then it kept saying the signal was very weak and that it was about to lose signal every time I went further than about 90m for the rest of the flight. Not sure if this is related but the altitude was also completely wrong, by the time I got to the ground and landed it said I was flying at -30m (-100ft)! I would really appreciate some advice as this has made me quite paranoid to take it out again in case it loses signal again when I'm much further away and doesn't activate return to home. Also I'm just practicing for now but I do want to take advantage of that 5km range at some point!