it is not an enemy, just you commands fail to register like 50-70% of times, it is especially bad during parts when you are down and need to press specific actions. If you do it slow, you will be just raped, because of how slow is it, but if you are spamming each button to make it faster sometimes getting up progress just goes back, because you press wrong button, and you are still going to be raped.That is weird, does it feel like the enemy's attack bars stutter? Is it for all fights or certain ones?
I downloaded a fresh copy from the main page and did not notice any stuttering or slowdowns against the first few fights.