Score parameter of the question in free format "multiple answer"

I am currently facing a problem on Storyline 360.

I made a module (very simple) with clickable icons that links to PDF files.

We want to get feedback on how many of the cards were clicked via their LMS.

I had the idea of modifying my page and converting it into a free format question "multiple answers".

However, Storyline doesn't allow us to award one point per correct answer. It's either right or wrong (100 or 0%)

So I added a Q1Score variable that increments by 1 when the person clicks on an icon (using a "add value 1 to Q1Score when image1 status is visited" trigger).
In the question parameters I put;
- "none" in Return
- "none" in Score
- I linked this question slide to my result slide which is just after

In my results slide, I added a trigger "assign Q1.ScorePoints the variable Q1Score when the slide timeline starts".
Problem... it doesn't work.

I also tried adding the value 1 directly to the "Q1.ScorePoints" variable when the image status is visited. And this for each image to click. But it doesn't work any better.

Would you have an idea to be able to return the information of the number of PDFs viewed on the LMS?

Thanks in advance