Hi it is very weird indeed. In this case I would rather disagree with Dad3353 because since it happened twice in the same place, it is not bad luck. There is a problem of some sort.
See if this helps. The string snaps between the tuner and the nut. Correct? That can only mean that when you increase the tension of the string with the tuner the nut does not let it move freely and creates some sort of weird tension. Makes sense to me but, I am just guessing.