MATEK F405 Rover/Boat problem

Hardware Rovers and boats
1

Hi, all.
I try to configurate my next ardu boat. My first one, was made on APM2.8 and all rover function worked fine (I used old rover firmware with skid options).
Now I try to configurate MATEK F405 STD board.

  1. My first problem is compass. When I connect the U-BLOX NEO-6M, all I2C functions go crazy.

  2. My second problem is rover steering.
    I use S1 channel for left engine and S3 channel for right engine

This are my paramets:
RCMAP-
RCMAP_THROTTLE 3
RCMAP_ROLL 1

SERVO1_FUNCTION 73
SERVO3_FUNCTION 74

FRAME_CLASS 2 - boat

When I use servo function 73 and 74 all motors are dead. Only SERVO_FUNCTION 53 cooparate with CH3 (throttle stick) and SERVO_FUNCTION 26 (GoundSteer ) make CH1 alive (roll stick).

What else can I check? Why SERVO1_FUNCTION 73
SERVO3_FUNCTION 74 doesn’t work properly?

Thank you in advance for any advice.