What rules follow the align settings in Adobe XD?

Hello Community,

since I am used to the alignment in Adobe Illustrator, I often used the function to align sth. to a key object, so that this object remains its place and the others use it as a kind of reference point by clicking on that obect after selecting everything that needs to be aligned.

So in Adobe XD it seems very random to me. When I select two objects and press center they are often centered on the whole artboard instead of what is higher in the layer stack being centered on the lower one. So they move both and I have to revert the step and try to work by manually editing the pixel positions. So far I did not found any rule or how to tell XD when I need artboard centering and when one object should center on an other. And if so, how to tell it, which object should use which one as key object?

Thank you very much for your help and have an amazing day!