Only one motor spins

Hello, I have a boat using ardupilot in mission planner but only one motor is spinning. When I connect power to the esc’s they start beeping rapidly, and when I turn up the throttle only one motor starts spinning. If I reverse the esc’s the other motor will start spinning. I don’t think the problem is with the esc’s because when I connect them directly to the rc receiver they both spin.

Does anyone know what the problem could be?

After re calibrating the esc’s none of the motors spin when connected to the flight controller (pixhack)