Seems odd both controllers are not working.
If both in-boat and underwater LEDs work in sync, then it could make sense that both are not working, as the commands comes from the Vision. I also think that the RGB signal to the LL box, would come from the ITC controller.
The LL OEM components may be different, but all their other power boxes ive handles, had an ON/OFF switch. But this would only power off the that controller, not the other controller.