DIAGNOSIS That gurgling is usually air in the water pump line, and the buzzing is often the pump straining. It happens when the water level gets very low or if the reservoir wasn't seated perfectly after a refill.
FIX 1) Turn the ice maker off. 2) Unplug it from the wall for 30 seconds. 3) Remove the water reservoir, check that it's filled properly (above MIN), and re-install it, pressing down firmly on the back to ensure it's fully engaged. 4) Plug the unit back in and turn it on. The noise should stop as the pump primes itself with a full column of water.
IF THAT DIDN'T WORK If the buzzing continues, there might be a small piece of ice or mineral scale lodged in the pump or the inlet. You'll need to run a cleaning cycle. Use the official cleaner or a mix of vinegar and water as per , running it through a full cycle to dislodge any blockages.
HEADS UP That pump buzzing can also be a sign you're using very hard water. If you continue to hear it even after reseating the reservoir, consider using filtered or distilled water to reduce scale buildup.