I start saying lucky because I do have prop gaurds, when landing with auto land, bird touches down but likes to tip back (lucky it has sit on the gaurds) and I pull sticks straight down and hold and bird dosnt throttle down. happened three times ive flown it four, all in beginner mode. do I need to calibrate something? I do have landing gear extenders could that be it? fairly level groung im landing on.