MailJet nested loops

we are building our emails with mailJet which works fine so far. Our current problem is, that we would like to have a loop within a loop within a loop (so nested loops) the first loop works fine, and also the second inner loop is working fine, but the third one isn't working anymore:

{% for trip in var:trips %}
{{trip.id}}

{% for tripSegment in trip.tripSegments %}

{% for tripBreak in tripSegment.breaks %}
{{tripBreak.duration}}
{% endfor %}

{% endfor %}

Distance: {{trip.totalDistance}} km

{% endfor %}

This is in our template. If I remove the inner loop with the breaks, everything is fine.

If I enable the Template Error Reporting I get the following message:

X-MJ-ErrorMessage: "tripSegment.breaks" is not an array value

but if I try to print it with {{tripSegment.breaks}} I get the message:

X-MJ-ErrorMessage: Array values cannot be printed: tripSegment.breaks

and the field is definetly an array, like the trips or tripSegments, so basically it should work.

What am I doing wrong for nested loops in MailJet?

Edit:

My Object Structure, I send to Mailjet looks like this:

"Vars": {
    "trips": [
        "id": 1,
        "tripSegments":[
            {
                "id":2,
                "distance": 100,
                "breaks":[
                    {
                        "duration":15
                    },{
                        "duration":20
                    }
                ]
            },{
                "id":3,
                "distance": 200,
                "breaks":[
                    {
                        "duration":10
                    },{
                        "duration":30
                    }
                ]
            },{
                "id":4,
                "distance": 200,
                "breaks":[
                ]
            },
        ]
    ]
}

As we were in discussion with the MailJet Support [1], it turns out that there is a bug in the WYSIWYG editor of MailJet.

the multiple nested loops work, if you use them within a HTML Block and not directly in the WYSIWYG Editor.

They are working on that.

[1] https://app.mailjet.com/support/ticket/21e111b3be8630214cc082845f6cf976