Bluerov2 control fine tuning

So we are hoping to get some tips on control calibration. We are using a standard game controller on our ROV, we’ve calibrated the IMU and also done the button mapping from motors to control. However, the movement is not intuitive. For example, we have to push both controller button left to go forward, and both button right to go backward, and there’s no button we could push to dive or rise up. Is there something we should be aware of? Or is there a tutorial video or guidebook on control calibration/mapping so that we can get intuitive control on the ROV?
Thanks!

@searover2021

Your controls are abnormal. The left joystick controls the lateral movement, while the right joystick controls the depth and yaw rotation.