The vehicle's motor is not rotating properly

I modified the vehicle parameters as I checked on the forum.
After the vehicle takes off 50cm from the ground, the rpm of the motor of 1,3,6 (CW) or 2,4,5 (CCW) is significantly reduced and the vehicle is not stabilized.

please tell me the solution

p.s mode: stabilize


(RC1 : Ail , RC2 : Ele , RC3 : Thr , RC4 : Rud)

(Motor PWM)