you may want to check to see if REVO mixing is active. REVO mix should be disabled with the GY401 .

with the humbird cp this may not be the case, but im not familiar with the PG 03.

to set the tail rotor machanics. a good place to start is to center the servo and put the arm on at 90 degrees from tail push rod, ,move the trim all the way to left. and set the tail rotor as close to 0deg pitch as you can. then center the trim and you should be set close

to fine tune start in HH mode take off and hover switch to NORMAL mode and trim so the tail is steady. then land and stop the heli. turn off and back on in HH mode. now leave rudder trim alone.