jsonata : complexe expression not working?

Hi,

I tried theses expressions, but nothing display

1. {{$join(specificRequest.certificationCategory)}}
2. {% conditional-section expr(specificRequest.certificationCategory != null) %}Non{% end-section %}
3. {% conditional-section expr(“FORMATION_ACTIONS” in specificRequest.certificationCategory) %}has FA{% end-section %}
4. {% conditional-section expr($contains($join(specificRequest.certificationCategory), “COMPETENCE_ASSESSMENT”)) %}tototoot {% end-section %}
5. {{expr($count(specificRequest.certificationCategory))}}

The first displays:

FORMATION_ACTIONSCOMPETENCE_ASSESSMENTEXPERIENCE_ACQUISITION_ACTIONSLEARNING_ACTIONS

The second displays the text correctly

The third and fourth display nothing

The last displays 4

The json looks like that, and everythongs works on jsonata.

{
"specificRequest": {
    "certificationCategory": ["FORMATION_ACTIONS", "COMPETENCE_ASSESSMENT"]
}
}