S_function cycled several steps per simulation step. How to control it?

I have attached an example of the next problem:

In simulink a simple S-function with at least one variable input will be cycled several steps during a single simulation step. I added another S-function that doesn't have any inputs. Both do the same thing, compute the number of times they have been played. I added the same computation with simulink basic blocks to have a reference. The number of cycles the S-function is played varies according to the nature of the input(s).

The final use is not counting the steps, these counters were created only to show the problem narrowing down to the most basic structure that includes the persistent function (needed for the final use).