Hoppers fire double

Hoppers now appear to push items downwards simultanious to when they suck them up from above.
That means that in a vertical hopper tower, there will be 2 items at a time moving downwards.

This won't happen if the top hopper isn't facing down onto the other hopper underneath.

Steps to reproduce:
1. build a hopper tower of at least 3 hoppers
2. put a stack of items in the one on the top
3. observe the behavior of the hoppers
Gfycat of the process