Play service has an unexpected behaviour.

So i am using this event newStep as above complete description is given.

MY USECASE:

I have two sequences in my animation and each has different steps so for example I have declared my array in home.js  -->  MAIN ARRAY= [1,2,3,4,5]

Sequence 1 = [1,3,5]

Sequence 2 = [2,4]

Now according to the selection of the sequence either it is sequence 1 or sequence 2 I will fill my temp array and just go on those steps. 

My function below newStep to get the steps from the animation and then match with my MAIN ARRAY and then get only steps which we have in the sequence which we have selected.

$scope.$on("newStep", function (evt, arg) {
//Triggered by going to a new step in an animation sequence.

let currentStepName = arg.match(/\(\d+\/\d+\) (.*)/)[1];
let currentStepElement = MainArray.find((x) => x.stepName == currentStepName);

if (!currentArray[arg.match(/\d+/)[0]]) {
currentArray[arg.match(/\d+/)[0]] = currentStepElement;
}});

Now my second function for the playing of the animation with the play service from the model is as below:

$scope.playBtnPressed = function () {
//original function
$scope.view.wdg['model-1'].currentStep = currentStep;

$timeout(function () {
$scope.app.fn.triggerWidgetService("model-1", "play");
}, 500);
};

now when i click on the play button which executes the service of Play from the model. It changes my step also like what i am doing with the forward function. for example if i am on step 1 and click play button then it moves to step 2. WHY IS LIKE THAT?

forward function ( which performs to go the next step)

$scope.stepForward = function () {
// set the marker for newStep
if (currentStep < maxSteps) currentStep++;
$scope.setWidgetProp("model-1", "currentStep", currentStep);

I am looking for the brief answers with the information as much as you can give. I am new to vuforia studio world. 

My Vuforia version : 9.11.4.0