Move-copy a component-instance without creating a new component?

I have a dynamic component of a window frame, that i place on my house model. Now i Move-copy the placed instance all over the house.
In some cases, there was a new instance of the component created as intended, but often there was a new component created…
It looks random to me what happens when, but i guess it’s not…

What’s the logic here, what triggers the component-copy vs. instance-creation?
Can it be avoided?
Can there be an alert/question about “instanciate or copy”? Maybe via a plugin?

PS:
Is there a shortcut to replace all instances of component-copies with the original component?

post withdrawn…awaiting deletion.