Power locks

I had a 2014 Toyota Highlander, all of the power locks stopped working after a few months. Toyota replaced each one at least 2 times, and the front drivers door was repaired 4 times. The dealership decided it would give me a great deal on a new car after many trips to repair the same issue. I now have a 2016 Toyota 4Runner, it is not yet a year old and both the front, and passenger lock actuators have stopped working. I am taking it to the dealership tomorrow for repair. They seem clueless, and have no explanation on why this keeps happening. Had multiple issues with the power locks. Any idea why this keeps happening?