Thats on purpose to cut down on lag. So when using machines that need hoppers you have to make some adjustments to compensate for the 3 items vs 1. There are some designs that just wont work though unfortunately.

Item sorters will still work but when a lot of items are moving over the hoppers they will push past the intended hopper. The way I have made them work is to have 2 or 3 sorters for each item as well as an overflow section of chests to catch what still makes it through.

Here is the tutorial I used as a starting point.

Also as a side note any potion lab that uses a a minecart and hopper set up dont work at all. The ingredients get mixed up  and I could not figure out how to make it work and had to change to this style potion lab.

Just take the concept of these builds and make them fit your base 🙂

enjoy and good luck

if you need assistance, AstroTech R&D has developed work-arounds for all of the weird anti-lag redstone stuff

Amin_H_Nasser wrote:

Penguin Technologies, Inc. has also devised item sorters and other devises that compensate for bizarre redstone.

This is a load of bs and proof that anandak has no idea what he is talking about. Item sorters still work just as well using the same set up as before, just transfer 3 items at a time instead of 1. This is not what I would call bizarre redstone. (On second thought, it might be bizarre for the simple minded Penguin Technologies, Inc.)