I have a peculiar incident to report, where by my quad running the latest software from MP (3.0.1), appeared to lose radio contact with the TX on at least 3 occasions. I flew a total of 3 batteries and all flights experienced the same issue. The issue is where the quad at a random point stops taking any input from the TX (even at distances of only 20 - 50 m and less) and appeared to enter a self-leveling mode, where I have no control. The faults all happened in stabilise mode and the first two were recoverable (the copter moved slowly and held an altitude and I was able to pull it from the sky), but the last flight resulted in a complete loss of control and now the quad is stuck in tree quite high up. Even turning my TX off and on again didn't help establish radio control while the quad was drifting out of control (only power cycling the controller gets rid of the issue when it's on the ground).
What could be causing this? I was hoping to find particular conditions/circumstances to replicate the issue, but it just seems to intermittently occur.
I upgraded to the latest PPM encoder, and I am using a 9X with custom firmware and FrSky 2.4 GHz modules. I'm also using V2 hardware.