I can't upload any pictures because it says that the file is too big but it seems that your server has a duplication glitch that will sometimes put stacks of items on the ground without taking any out of the chest. There have been multiple occurrences personally which all happened in a melon farm with melons. I have 2 screenshots of when this happened. One time it put 4700 melon on the ground another it put 3540 and another put 13667 on the ground! That is not a typo.