sizcoz My example can work on higher speeds in C3 with bullet stepping. (or if you enlarge sprites)
It's the matter of how big are the sprites, and how many pixels the enemy is moving on every tick. If it travels the distance bigger than its own width in one tick, it can no longer detect walls and corners correctly.
Basically, it's the same issue as when a very fast moving bullet can sometimes go through solid walls, instead of bouncing.