In a setup where you have a powered hopper below a brewing stand and another hopper with waterr bottles facing into it from the side, the brewing stand will initially fill normally. Then when the bottles are released by unpowering the hopper below, the bottles will flow out, but no new ones will be pulled into the brewing stand.
This was still working correctly in 1.11.
I can confirm this in Minecraft 1.11.2. This worked perfectly for me in 1.11.1. If manually placing bottles into the brewing stand, the potions are brewed properly, but no bottles will enter the brewing stand after initially placing down the stand.