If I want earn nether star fragments from nether bees in alveary is it real? On alveary placed wooden slabs.

Can you explain in more detail?

To get nether star fragments from bees I need (on 1 Sep 2017) skull on the apiary, but I can't place skull on alveary because there are wooden slabs

In the next update I've extended the range both vertically and around the block so it no longer needs to be on top, just nearby