Hoppers and brewing station

I was trying to make an auto brewing machine, but I found out when the whole procces ends, the hopper that should put new water blottles in doesn't detect that there is empty space for bottles, but when I put a bottle and remove it, it seems that the slot I put it updates and then the hopper can put another bottle in that slot. (If there is any English error, sorry. I'm not from an English speaker country)