Custom Submit button not working properly with delayed states

Hello everybody!

I am in trouble, I really don't know why it is not working !! Hope that you will save me

So I have created a custom Submit button (OK button) to  validate all of my exercise page templates outside the player (I don't want to use the Submit from the player):

I put an hotspot that simulate the Submit interaction when the user clicks on:

In this case, I got problems with Drag and drop exercises. I generally use a specific function of this exercise type in FEEDBACK: Delayed iteam drop states until interaction is submitted.

This option is mandatory in the pedagogy in order to show after the first attempt to the trainee which answer is correct or not with a Green/orange color scheme:

Orange shows incorrect and green correct. The problem is that this functionality does not work when I use the custom OK button but works perfectly when I use the standard Submit button from the player.

I really don't understands why... I configured exactly in the same way the OK button as the standard Submit button.

Do you know if it is a failure of Storyline or my own?

Thanks in advance for your support!

Julien