Put the summary of the bug you meet here

• What I expected to happen was that the hopper be updated with a redstone signal as usual

• What really happened was that the hopper remains in the original state no matter what you do. To assign an update, we must leave the game and restart it.

You can view the image in a link. This circuit worked very well. In summary, on the hopper there is normally a block placed on the face that I show with my avatar. Here, nothing (I hear in signal redstone) is bound with this hopper, yet it does not empty its contained in the brewing stand