Servo jitters in stabilize and FBWA

I’m using Pixhawk in flying wing differential spoiler setup and arming with rudder and safety button.

Issues:

  • with safety button led blinking I can arm model with rudder (confirmed in mission planner)
  • If model is armed OLED I2C display only indicates armed and no more information (additional basic information should be keep in display)
  • If I set ARMING_REQUIRE,0 OLED never displays info just that is armed (additional basic information should be keep in display)
  • If I enable safety switch in button (solid led) and not in rudder if flight mode is ‘stabilize’ or ‘FBWA’ servos have no jitters with 0% throttle but has I increase throttle jitters increase until 100% throttle. This issue does not happen in Auto, RTL or FBWB modes
  • If I enable safety switch in button (solid led) and also arm in rudder no servo jitters happens in ‘stabilize’ or ‘FBWA’ or any mode

Is this normal behavior?

Question:
If I enable EK3_ENABLE,1 and select EK3 for AHRS_EKF_TYPE should I EK2_ENABLE,0?