it sounds like the door lock actuator. in my industry, ford has had more issues with door lock actuators/door pin assemblys than other manufacturers. (except honda) since the door pin and actuator are in the same housing, it makes it very difficult to work with, and the most common is just a replacement. but i have lost count how many door locks i have had to replace in ford vehicles in the past, including my own personal vehicle. the most common issue is the actuator does not go up all the way, or goes to far and starts its down cycle. either way, the actuator is not in the correct location. so when you open the door, the first pull of the handle will set the actuator in the correct position and then the second pull will engage the latch. not saying this is the case, but definitely sounds like it. i have put in hundereds, if not a thousand door lock actuators in vehicles. i can replicate this problem with an aftermarket actuator any time.