out of me and I can't figure out for the life of me what is causing the issue. I have searched everywhere above and beyond for an answer with no luck. As the title says my quadcopter flips upside down in cleanflight. I'm using the full naze32 with cleanflight 1.9 connected to my D4r receiver via CPPM. My Lumenier 12a NFET autoshot ESCs are also connected to the servo inputs. I also have the discovery buzzer, voltage, and telemetry pins connected to the board.Now the problem only shows up intermittently mainly after landing. After calibrating the accelerometer and gyro on flat surface I'm able to arm and fly the copter. Then when I land and try to arm it again it doesn't want to arm, even if I power the quad and transmitter down and back up. If I connect the quad to cleanflight in this state it shows the quad is perfectly upside down. What causes this? I've tried everything like reflashing cleanflight and even trying a new board. I get the feeling that a sensor is causing this because when I used a new naze 32 acro instead this problem doesn't show up but it does show up again when using a new full naze 32. Yes I have already swapped the full naze with a new one and the problem is back. The only thing I could think of is that the VTX which sits above the Naze attached to the topplate is causing something to go haywire. BTW the frame is CF QAV250 and the motors are T-motor 1806 2300kv but the Naze is in a plastic case and insulated from the frame. What could cause this???