Oneshot enemies (The Elder Scrolls 5: Skyrim)

After recently enemies began to shotit once or twice. Provided that the health of more than half, and sometimes even full. During the battle animation is the goal, only from the enemy, stupidly killed for no reason, even with the assigned unit ...replay several times already - still the same. It's a failure in the matrix or so and think great Randomized? 4 times in a row isn't funny once, okay once, but that's Ko Phi Phi is too often the case.
Thanks in advance for help..
PS. the enemies are not above the level of the character, same thing with dragons.