Changes detection doesn't work properly in Angular2

In ngOnInit() I have a subscription on a Subject, which sends new data when I get a new response in my service from the EventSource:

this._orderService.onNewOrderLoaded$
  .subscribe(order => {
    this.orders.push(order)
    this.orders.sort((a, b) => b.id - a.id)
    this.orders = this.orders.slice()
    this.notify()
  })

this._orderService.openSSEConnection()

In my template I have a simple table, that displays orders:

<tr *ngFor="let order of orders">
...
</tr>

But component doesn't rerender when in subscription in ngOnInit() I get new orders and change orders' model using .slice(). So I detect changes manualy using this._ref.detectChanges(). It is the first question: How can I rerender component without detectChanges() when I get a new order in subscription?

And the seconds problem is that when I use detectChanges() and rerender table of orders, (click) method doesn't update model of new order too. (click) of <td></td> calls function:

viewOrder(order: Order) {
    this.selectedOrder = { ...order }
    this.isInfoModalOpened = true
}

This function changes isInfoModalOpened and selectedOrder so modal component can be displayed:

<app-modal-component *ngIf="isInfoModalOpened" [order]="selectedOrder">

But it doesn't work too, so or I need to call detectChanges() manualy or I need to click on some element, that will cause changes detection.