Right side tilt servo jitter - Skywalker X8 VTOL

Hi

I have problem with right side tilt servo jitter-like issue whenever roll key in.
I thought it’s caused by interference from other devices but it doesn’t look like it.

My configuration
SERVO1_FUNCTION = 77 (Elevon Left )
SERVO2_FUNCTION = 75 ( tilt_Left )
SERVO3_FUNCTION = 34 ( Motor 2 )
SERVO4_FUNCTION = 78 ( Elevon Right )
SERVO5_FUNCTION = 76 ( tilt_Right )
SERVO6_FUNCTION = 33 ( Motor 1 )
SERVO9_FUNCTION = 10 ( Cam_Trigger )
SERVO10_FUNCTION = 1 ( RC Passthrough. Cam swaffing )
SERVO12_FUNCTION = 36 ( Motor 4 )
SERVO13_FUNCTION = Power


As seen above Arduplane never send pwm to servo5( tilt_right ) but it jitters

I’ve also test it by “Servo Tester” but it has NO Problem

pls refer to
videos here - https://photos.app.goo.gl/ADZ3nRJ9y2Na5wZ86
( 2nd video done by Servo Tester )
log here - https://drive.google.com/file/d/1s3nD3yVCyEGLFdDb_W_r1lWOQMfO-QIP/view?usp=sharing

Very appreciated if you would let me know any clues