"I Have same problem
pixhawk , latest ver AC3.5.4
tiger motor mn3510 kv 360
tiger esc 40a
AUW 5.4kg , 2.7kg fram + 2.7kg battery (Lipo 6s,22A)
battery install at CG in bottom the copter
use mag+GPS with 30cm distance with any electrical…"
"@patrick ,Hi, in previous page you mention that use 2 watt transmitter on your UAV, Can I ask what 's your transmitter?
Do you use a usb dongle and 2 watt Amp or your transmitter has 2 watt RF output?"