Minecart with Hopper does not pick up items that are lying on a block directly above the track

In previous versions, the hopper minecart was supposed to pick up items that were sitting on top of the block directly above the track. However, in the current snapshot (17w50a) it seems as though it does not work.

I do not know if this purpose has been changed and this is the intended behavior or if this is a bug, but I could not find any other bug reports of this specific issue.