Gaia 190 hybrid

hello I would appreciate if you could help me, my company has recently buy gaia 190 hybrid drone from foxtech if you know.we have build it with a pixhack2.1 blue cube and here gps.it flies good in alt hold mode but when I switch it in loiter mode starts shakes.drone holds the position but shakes specially when I steer in any direction and then loose my stick free…when it stops from moving. please help