Angular ExpressionChangedAfterItHasBeenCheckedError after click event

folks. I have an Angular sample app at stackblitz (https://stackblitz.com/edit/angular-gitter-utwsoc) where i'm reproducing a change detection error from my real application. I have a list of QuestionComponents in the app. Items are successfully rendered (Initialized, Checked ...) in the AppComponent initialization, but i'm getting ExpressionChangedAfterItHasBeenCheckedError when i try do add a new QuestionComponent in the list. Another specific thing is that the error just shows up if the initialContent property is set to '', undefined or null. If the value of this property is something different, the error does not shows up.

I discovered some workarounds, but what i really want to know is a kind of deep explanation about the behavior. (A change detection explanation maybe). Thanks!