Brewing Station Does Not work Since Hoppers Cannot Let Water Bottles Go Through

This bug was found by my friend Mycomy.
The hopper with a sign on it was filled with water bottles.
Once the brewed potions flew into that little chest, fresh new water bottles could not go through the hopper into the brewing stand.
Since that, Mycomy's brewing station was totally broken. He believed this was a BUG appeared in 1.11.2 and asked me to report it.