Library issue with place and copy, layer information lost, library elements grouped

Since we switched from 2017 to cc 2018 Illustrator does not remember the layers if we use the function place and copy by rightclicking the elements inside the library window.
It still works on Illustrator cc 2017 but on 2018 all Elements are grouped together so that everything is placed on one layer.
The function remember layers in the layer window is activated but i guess the problem is that all elements are grouped and then the layer Information is lost.

If you open the library element, mark all and then copy paste Illustrator remembers the layers.

Someone any idea how to solve this problem?

Thanks in advance.