Ngzone does not update item elements outside of label and note

I’m displaying a list of phonecalls in my app that gets filled through an API request on ionViewLoad() for the first time when the app is opened and then gets updated through push-notification.

I iterate over the list with ngFor and display the objects in a ion-list using ion-item.
The structure of my ion-items is

 <h2>{{ sItem.businesspartner.name1 }}</h2>

Works fine for the initial data from the API.
After that I listen for push notifications and add them to the list using => this.phonecalls.push(newphonecall));

These updates don’t get displayed. First I thought my object structure was off but then I noticed it works for everything I render in ion-label or ion-note for example
but not for p h2 and so on. So the initial data get rendered fine in p and ion-note of updates I only see the part that’s in ion elements.
Any ideas how I can get this to work or ion elements that give me a similiar result?