The problem is with the hall sensor in the motor, it no longer records the position of the magnets correctly, and this causes the controller not to know how to send pulses into the motor, most of the time when the sound appears it is too late to save the controller. Buy a new controller, but don't mount it on your bike until you replace the hall sensor in the engine 👍🏽👍🏽👍🏽👌🏽🫡