How to repeat the cellmerging in XLSX with openTBS?

Question

Let me try to describe the problem in words. I have a headline in my array which should be centered in two merged cells. When opentbs is looping throug my array, only the first headline is in a merged cell, for all upcoming headlines the cellmerging gets lost.

The Array is similar to this:

$data = [
    'name' => 'district one',
    'streets' => [
        [
            'name' => 'first street',
            'description' => 'first text',
        ],
        [
            'name' => 'second street',
            'description' => 'second text',
        ]
    ],
    'name' => 'district two',
    'streets' => [
        [
            'name' => 'third street',
            'description' => 'third text',
        ],
        [
            'name' => 'fourth street',
            'description' => 'fourth text',
        ]
    ],
]

The cell structure i want to reach is like this:

Cellstructure

and this is the code of template:

[data;block=begin;sub1=streets] 
[data.name;block=tbs.row]   
[data_sub1;block=begin] 
[data_sub1.name]    [data_sub1.description]
[data_sub1;block=end]   
[data;block=end]

here is the templatecode and the result in one img:

templatecode an result

How to repeat the cellmerging with openTBS?