Strange problem with an array

Hi to all

I have a strange problem. Perfectly functional game in all its parts. I decided to improve the graphic appearance I inserted an animation in the procedure where an elent of an array with a "pop on x" is deleted

In the oridignary game, an element of the array is correctly eliminated starting from the phonograph. In the modification delete 4 elements at a time. In the proceedings only passes once.

What happens and how can I remedy the problem?

Thank you