Calling IncreaseTestIndex() from within the Blueprint causes also a change of the Address.
It seams that calling the IncreaseTestIndex() from the BP creates a new instance and hence resets the value of TestIndex to 0. After that it increases the value to 1 and prints that new value during the tick.
Still not understanding what is going on.
I am going to test if adding the component within the constructor will change anything. But I do not think so.