Special characters in Question Form entries

Hi everyone, 

Here's what I noticed when building a question in SL2 :

Let's take a Multiple Choice question.

Whenever my responses start with a special character, like '%' or '$', the LMS will not be able to retrieve the data in the SCORM Report (it says : learner_response = undefined, same for correct_response / see SCORMCloud screenshot in attachments)

 

This only happens when the character is placed at the beginning of the string. If I move it to another place, everything works just fine.

So, are there any restrictions regarding this point? Maybe SCORM doesn't allow special characters at the beginning of the strings?

My sample project is attached.

Any thoughts will be much appreciated :) Thanks all

Guillaume