Troubleshooting VEX motor controller 29

I have a question about VEX motor controller 29.

I am using the VEX 393 motors with Arduino. I have created a PCB and connected 4 controllers to it.
Now when I test the motors, 2 of the motors run perfectly but the other two motors don’t run.
I have checked that the motors are all working fine, but something is not right with two of the controllers.

Is there a good troubleshooting that I can perform to check if the controllers are working or not?
I have checked the wiring and I am getting all the continuities correctly.

Thanks.