I don't know why. I can't get your black object to do anything - not even a basic collision will work with it.
What I did do was:
- Delete the black enemy.
- Clone the pink enemy and made a new one - enemy 3
- Put that everywhere there had been a black enemy.
- Removed the events that I had given you from the global list - put them in frame 2.
- Changed them to work with the qualifier - bad apple - not the individual enemy (which is why I had to take it out of global events)
You could try that - it seemed to work.
Is there a reason you want that pixel by pixel loop movement? Because you could give your enemy just a normal movement like bouncing ball, select only left and right - put a block left / block right - when it collides with block left - face the other direction - and vice versa. No loops needed. Only where you have only 1 blocker you would need two - one for the left and one for the right. You can change their speed to whatever you want it to be as well.