Why is the attribute dropdown field all the time is getting selected?

I just simply substitute the values for a dropdownlist when the value of another field:
replaceCarsDropDown function()
{
$.ajax({
 url : '$urlGetDrivers',
 type : 'post',
 data : {
 id : $('#panel_car_value_select2').val(),
 //order_id: $model->id
},
 success : function(data){
$('#panel-driver_id').empty();
$('#panel-driver_id').append($(data).children());
}
})
}

Where $('#panel-driver_id') ID dropdown sheet

The data the server returns this:
$result = $car->getDrivers();
 $arr = [];
 if ($result)
{
 foreach ($result as $key => $item)
{
 $arr[$item['id']] = $item['name'].' '.$item['surname'];
}
}

 $return = Html::dropDownList('drop', null, $arr, [
 'prompt' => '-- Select --'
 ]);


A sample query result:
"
<select name="\"drop\"">\n<option value="\"\"">-- Select --</option>\n<option value="\"2\"">asdf adf</option>\n</select>"
July 8th 19 at 11:13
1 answer
July 8th 19 at 11:15
Maybe it has something to do with validation from Yii, try to disable it.

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