Put the summary of the bug you're having here

What I expected to happen was...:
So I am trying to make a simple farm where the sugar can is pushed by a piston and is collected by a hopper in a minecart and transferred to another hopper than a chest.

What actually happened was...:
The hopper in a minecart is having an issue where the items is not being transferred to the other hoppers. 

Steps to Reproduce:
1. Place a chest and a hopper going into that chest.
2. Place a rail and a minecart with a hopper over that hopper.
3. Place a block over the minecart.

4. drop a block and the hopper under will collect it

5. The hopper will jam, probably not. Try different items.