I have a simple setup of one blueprint with a box component with an OnComponentBeginOverlap event. When an actor enters the box, it is added to an array. The problem is that sometimes BeginOverlap gets called twice because EndOverlap gets called. This doesn’t happen every time and seems to be completely random when it does. EndOverlap shouldn’t be getting called because the actor never leaves the box once it enters. In fact, it just stops about half way into the box every time.
Well, I figured out it has something to do with the movement of the actors as they hit the box. I was interpolating their location and rotation, but if I just teleport them to the box, BeginOverlap only gets called once. It could be they were rotating in and out of the box faster than I could see it.
thanks man , ur answer was helpful , i had the same problem trying to do as the tutorials but in my way 
- YouTube)
after reading this i added doOnce and a Delay and it worked perfectly 
sorry that the 2nd pic (solution) is not clear but here is where i put doOnce and Delay