Ionic Side Menu Problem/Bug

Hello Everybody,

I dont know if its a bug or just my fault.
I have a sidemenu in my ionic 3 app. This sidemenu contains an ion-list with some dynamic content (some objects). During the runtime of the app these objects increases.
Now the problem/bug:
If I open the menu by dragging, the Ion List will not be updated. But if I open by menuToggle button, the list gets updated.

What is the problem. Or is it a bug?

HTML - the sidemenu:

Any help in solving this would be greatly appreciated. Thanks!