when ng-repeat list of folders updates wrong - angularjs

Question

I have receive listof objects with names: F1,F2,F3,F4
when I make call to server, I receive new list F1,F2,F3,F5,F4
when I apdate ng-repeat list:
vm.folders = data.content.items;
it shows next list: F1,F2,F3,F4,F4
where am I wrong? here is my html code:
<div ng-repeat="folder in vm.folders track by $index" ng-init="openInput=false;">
<div layout="row" ng-init="folderName = vm.getIterationName(folder.metadata)" >
<div >
</div>
<div >
<span ng-click="showChildren[$index]=!showChildren[$index]" class="capitalize" ng-dblclick="openInput = true;$event.stopPropagation();" ng-show="!openInput">{{folderName}}</span>
</div>
</div>
</div>
js update method:
function updateIterations(data) {
if (data.ok === true) {
if(angular.toJson(vm.folders) != angular.toJson(data.content.items)) {
vm.folders = data.content.items;
}
} else if (data.ok == false) {
console.log ('Error:iteration request: {ok: false}');
$interval.cancel(intervalRequests);
}
}

Answer 1

fixed!
in
<span ng-click="showChildren[$index]=!showChildren[$index]" class="capitalize" ng-dblclick="openInput = true;$event.stopPropagation();" ng-show="!openInput">{{folderName}}</span>
instead of {{folderName}} i've used:
<span ng-click="showChildren[$index]=!showChildren[$index]" class="capitalize" ng-dblclick="openInput = true;$event.stopPropagation();" ng-show="!openInput">{{vm.getIterationName(folder.metadata)}}</span>