Hi Ricardo,
I believe this may be a storyline issue. I would recommend using javascript to set completion data to Moodle.
If you look at the learning heroes community you should find information there about executing javascript in your Storyline packages. We have had similar problems but you can set grades and set completion status by executing SCORM relevant javascript.
For example, we set completion status using the code;
SCORM_SetCompleted();
This is done by choosing a slide before the end and creating a trigger to execute javascript when the timeline starts.
I hope this helps with some of your query!
John